Joe, just a suggestion, but, I have always found that your best source of information like this can be found at your local marina talking to boaters that have had that type of work already done. They will be much better prepared to direct you to a good one and steer you away from the bad ones in your local area.
I belong to another forum and have read several very bad posts about Atlantic Towers. when I say bad, I mean VERY bad!
Not sure I would deal with them. So, be careful.
I also agree with the added weight that high up issue raised above.I had considered a hard top but did some thinking and decided to do a canvas top. works well, keeps the sun and rain off and doesn't add much weight at all.