I sail the Taipan at 185 lbs and have been competive with the other Taipan sailor in my area who is 140 lbs; in fact, I'm a lot better off with it over 10-12knots! I'm depowering the main significanty at 14 knots. It's a great boat and the large jib keeps plenty of power when adding a second guy. I've also sailed it in 16+ knots 2-up with main and spinnaker (no jib)--wow, what a ride!!! The boat is fast and nimble, and it makes me look like a better sailor than I really am. I've heard that the T4.9 cat-rigged champ in Australia is over 200lbs. There's quite a bit of hull volume for its length--much more than a H17, for example.

Having said that, I've seen the Fx-1 and I17R--they are quite a bit bigger than the Taipan in terms of hull size and rig size. If the Taipan relies on finesse and light weight for performance, the Fx-1 and I17R (and N5.5U) rely more on brute force. Probably very similar in final performance, but different in their approaches.

The lack of a US dealer is curious but not really an obstacle. I just called (you could also email) Greg or Jim, the designers/makers, and ordered one. Very simple. The real obstacle is cost. The exchange rate with Aus. is improving, though.

No used Taipan 4.9s are available in the US right now, and if one did come on the market it wouldn't last long as demand is higher than supply. (Note that the cost of the I17R and Fx-1 is also in the same range as the Taipan, and used ones are similarly scarce.) But a really viable option is to purchase a second hand Taipan from Australia and have it shipped. The build quality is of a standard than even the earliest boats are still stiff and competitive. A used Taipan can be had for well under 10K.

The new Blade F16 will be made in FL but will likely cost > 12K as only new ones will be available. The Stealth F16 is another option, but the hulls have quite a bit less volume than the Taipan and that might be an issue for you (it's a very nice boat, though).

Do you still have a N5.5? Another option would be to pick up another 5.5 or even a 5.0 and add a spinnaker--they would also make sweet one/two-handers. This would be the least expensive option. I'm sure the H17 is a bit of a dog for you, especially downwind. Adding the spinnaker to cat sailing has been one of the most enjoyable things for me, and it adds that hull-flying spark to the downwind ride.