You talking about buying someone else's hard top? Assuming that's the case, I think most (or all) should come with the mounting hardware attached directly. Unless they were purposely removed or discarded you should be fine. Might only be missing the rear bracket covers that I believe just velcro in place or the front windshield / roof liner thingamajig if anything.
The 2005 hard top should come with brackets two in rear, two in front. These are necessary otherwise your hardtop will fly off! There are also bracket covers, two in rear, one big one in front, which are cosmetic only.
I believe the 07+ has an extra middle rear bracket
you should be ok on the attachment points as the top's mounting hardware is "captured". Just go slow putting it on so you don't chip up paint. Get a friend to help you lower it onto the car during install/removal.