http://www.towerbiminis.com/ I have bought two biminis for my two Nautiques from these people and have loved them both. A friend of mine bought a MasterCraft and was really disappointed in the bimini the dealer put on. I referred him to these people and they built him one which he is thrilled with.
I know that they have, in their shop, the actual towers off a 2001 Air Nautique and a 2003 Super Air Nautique (not the boats, just the towers). The Correct Craft dealer in my area uses them for all their biminis. They might have other towers as well or know how to make the bimini for your boat just because they have done it before.
If they don't have the tower or the pattern you can measure your tower and have them built it based on that. The good news is that the biminis are fairly flexible so if the measurement is off by a 1/2 inch or so it isn't a disaster.
I recommend the stainless poles. They cost more but the bimini is so much stronger and stiff.
They are not cheap, but they are great biminis. They have the best tower mounts of anything I have seen (doesn't require drilling any holes in the tower, deck, windshield, etc).