Recommend a company for new convertible boot?

Yes, when I bought mine from legendary, I had to install all the snaps but the very center one, which they do to locate the boot for you!! They do send all the snaps, and the little die set to mushroom the snap stem! It was a pretty easy deal, but I did do it in the summer, and laid the boot out in indirect sunlight for awhile to soften it up to allow it to stretch easier!

ditto for my 68 barracuda