What I did with my moldings was take them off and lay them out,using a scraper and a blow dryer to make it nice, flat, and to get rid of the little waves. Then I hadmy dad help me by holding up the back half of the moulding while I alligned the front gap and he checked the rear to make sure they were pretty even, at this point I had already had the doublesided tape on and we made sure it was ligned up gap wise and we strated pushing it flush with the door in the middle and working our way out so no waves were in it and the gaps came out pretty good!
Both are great colors you do not see on too many fox body mustangs, I would go for metallic blue. Use billets because I am putting cobra Rs on mine lol jk put what ever you want on there it is your car and to be honest, it would look nice ether way. If you are interested in my project PM me and I will give you a link to my web page.
Pull the whole molding off and put new double sided tape on it and start from the front of the door and stick about 4" on it and press so its pretty much stuck on there and get a blow dryer and heat it up and as it warms up a bit, slowly put it on while pulling and stretching at the same time and after you do that to the whole door, at the end you should have that inch or 2 you needed. That stuff is kinda like base for kitchen and bathroom floors and some times it shrinks and you have to do that only you stick it with glue.