Tom,
For all around streetability, driveability, and simplicity, that system is great. I helped a friend put it on his 78 Elcamino. It is very simple to install, instructions are easy to follow, and you can adjust the engine operation from the stand alone unit. I believe that two barrell will only feed up to 270 hsp, but for a good all around street car, that is perfect.
You will be very happy with it. Especially the price and the fact it will still be a "stock" look with the air cleaner on.
However, if you are also shooting for some performance, take some time to look at the variety of aftermarket multi port systems out there. Not to mention, installing a stock style 1985-1987 Tune Port System from a F body or Vette has become very simple. I have seen complete intake systems going for around $250 or less at the car shows. The computer harness is about $250. You will need to pick up a used computer $25 (the TPI puters are cheap), and finally a high pressure fuel pump and air cleaner set up.
For about the same as the Pro Injection you can swap in a dependable and durable tuned port. You have to watch the year models as in the 1988 and up version got the different angle on the center bolts of the intake. You could still use it, but would have to hog out the hole and run a large washer (been there done it).
Either way you will have a ton of fun, and throw that choke, vacuum gauge, and tuning screw driver out the window.