Get ready to take a hit to the wallet when you are talking about weatherstrip and convertible top replacement.
You do have a few choices in regard to the weatherstrip. Some people prefer GM pieces only (myself included) and others use aftermarket. I have also heard positive comments on a company called Corvette Rubber. Typically, their prices are cheaper than GM and some have reported that when they receive the parts in the mail, they are actually GM pieces. Give the company a call beforehand if you are unsure.
As far as the convertible top itself goes, if you are going to have it installed by a professional, you are looking at $600.00 or so for removal/installation. My advice on the top that you choose for your car is to go NOS if you can get it. I have seen aftermarket tops on Corvettes and they are always lacking in fit/finish; they just don't look "right".
I happen to have the removal/installation video that details the procedure, and quite honestly, I would not attempt it. A seasoned installer takes many hours to remove the old top and install the new one. The weatherstripping has to be removed/reapplied, the top has to be removed from the frame, and if your headliner is in poor condition that should be removed/replaced as well. There's quite a bit of gluing involved as well.
About 8 weeks ago I had looked into this myself for my own car and the shop (the guy has been working on Corvette convertible tops and interiors for over 20 years) said that he would require the car to be left with him for 2 days. His installation price was $600.00.
You may want to get the video and take a look at it for yourself, and then decide. To me, something like the fit/appearance of a convertible top is something that I want to be as perfect as possible; I'd therefore leave it to a well seasoned professional.