Welcome to the 
First, congrats on knowing the first thing about buying a Corvette... Asking lots of questions first from people that have first hand experience. "It's good to learn from your mistakes. It's better learn from other people's mistakes."
As
Kane said, and he may even have been quoting me from long ago (or maybe I was quoting someone else long ago...can't even remember now! :L)
Buy the most Corvette you can afford!
Unless your shop & friends are going to do everything for free,
including parts acquisition, you'll spend more fixing the car than you will if you spend the money upfront on a working car. For example, Say you've got $10K to spend. You choices are an $8500 car that will need approximately $1500 in repairs, or there is a $10K car that will max your budget, doesn't really need any repairs. That $8500 car is going to require more than $1500 in repairs, guaranteed!
"How can I make such a guarantee?" Because on our old cars, once you start digging into it, you're going to find all kinds of other stuff that wasn't immediately noticeable and/or you're going to be in a position of, "Well, while we're here, we may as well replace/fix that too! Doesn't make sense not too. :eyerole"
Now that 4 hour, $1500 repair just became a 15 hour, $2500 repair. (There are many true stories about starting with a simple repair turning into a body-off restoration.)
So what does that leave you with? An $11K car that still isn't on the road. You could've had the $10K car, lots less assache, and been driving it instead of cursing it.
Regarding the two cars you have listed here... there's a couple of things to mention.
1) Use the knowledge base / model center here at the CAC to go through the various years. It's essentially the Corvette Black Book online. There were usually fairly significant changes made year to year, especially between 1979 & 1980. See what the changes were and if they impact your decision.
2) Your preference seems to be C3's, but not entirely based on body style since the 68-73,74-79,80-82 all have fairly distinct styling cues. Is the C3 attraction due mainly to the cost of the car?
3) Don't buy an "affordable" C3 vette thinking that you are going to have a rocket on the street. A newer 4-banger Civic driven by some punk 17 yr old will likely hand you a smug cup of defeat in almost all worthwhile performance categories. And it doesn't matter what the original factory specs were. 30+ years later of engine & driveline wear are not going to have the engine performing at factory spec (which, sadly, wasn't all that great to begin with, but it was the best you could get in that particular year).
4) The '79's L82 engine is no longer original, so don't let the "L82 option" sway you. "With the work that has been done, the motor should be putting out 235 - 245 HP."
Should be... at the crank? The wheels? Yeah, and by who's measurement? His repairs
should've fixed whatever he thought was the problem, but if it didn't, that's now going to be your problem. We often refer to this as "Bubba". "
It seems Bubba worked on this car and now I have to go back and do everything the right way." The guy "spent a good amount of time getting it usable as a daily driver"....is he in the business of flipping cars? Or is there a better reason he's dumping it, like, say he got in over his head? Don't let his mess become yours! (PS - The 1979 was heavier than the '80, so the additional engine power was negated to some extent.)
Does MI have emissions rules? He removed most of the emissions stuff from the engine. Is that going to pose a problem? In Ohio, it used to be that in order to get exempted from future checks, you had to first pass the e-check with factory parts installed. And if he made significant internal changes, for better or for worse, adding the smog stuff back on my not help anyways. This doesn't sound like a position you want to put yourself in.
Also, I can't tell for sure from the pics, but it looks like there may be a 1980 rear bumper on there with a center-mounted antenna. Not that that's a major distraction. It was common for people to put the '80 style bumpers on their '79s.
5) Between the two you've listed, I'd take the '80 for a few bucks less. I'm leery of what may or may not have been done on the '79. Maybe the guy is a great garage mechanic and really made it a nice driver. Or maybe he's Bubba and took an "OK" car and made it worse.
6) Knowing what I know now, personally I'm not sure I'd choose either of them. You didn't give a budget so we can't quite help you make a fully informed decision. I'm guessing the price of these cars plus the $1500 you said you'd have available to 'put in to it' gets you in the $6500 range. I'd start looking at $6500 cars and pass on these two. I've said it many times before in various threads here... Used vettes are
beyond numerous; There's tons of 'em out there. Don't let the money burn a hole in your pocket. Be patient. Find the car you
really want and not one that you're just willing to settle for. It's like settling on a girlfriend..."settling" always ends up a bad choice in the long run.
We at the CAC love helping new enthusiasts get in on the action while making good decisions along the way! And we love resto stories. Don't hesitate to ask questions. You'll get plenty of answers for everything along the way.
(PS - If you end up with an '80, let me know. I'll send you a GM service manual on CD
)
4LT GS Roadster
. It gets in your blood early in life, and there is nothing you can do. $50 bucks here, $100 there, and a $1,000 when your wife approves…...I got my first vette in college (before wife) because the insurance was cheaper than a 79 Trans-am at the time, and 25 years later I still have one. 
