I've done both a $100 dash cap and a $500 dash pad on E-bodies, so I've had a little experience and know some of the problems. If you go with a dash cap (our's was from Legendary), it can be pretty presentable, but making it look a little better than presentable involves some work. For example, the cap didn't wrap all the way around the dash edge over the instruments, so I had to add a strip of metal on to the light bar to hold the edge down. The A/C vents wanted to suck right through the openings because the holes were a little larger than they could have been. The bottom edge of the cap doesn't wrap under the pad above the glove box and ashtray but just ends straight down, so you have to carefully glue it down tight without smearing the silicone adhesive all over the place. Also, it's easier to put it in with the windshield out, but it certainly wouldn't be worth the risk of cracking a good windshield just to get it out of the way. The major issue with the dash cap in my opinion is that it expands and gets very wavy if you park the car in the sun on a warm day. It does go back close to the original form when cool, but it does warp. To deal with the deep cracks, I just used a sharp utility knike and cut the curled up edges off so the cap could lay flat. I didn't use a filler (but I have used that filler mentioned in the MM article on elastomeric bumper repair).
The pad is five times the cost, but once you've done it, the dash is taken care of, and you won't have to go back and redo it. Doing the pad is not very difficult, if you're comfortable taking the instrument cluster out and reconnecting correctly. I worked with an Ultimate Rides dash from AZ-Nick (on this web board). There are some fit problems with the repro pads as well. For example, the corners are a little rounded off where the pad meets the plastic bezels on either side of the instruments, and the pad was too fat on the right A-pillar so that molding had to be reshaped.
Your budget is your business, but if you can swing the dash pad rather than the cap, you will be much happier. After all, Christmas is coming, so maybe Santa can help a little.
