"Thinking about the FX-One because I will be sailing solo a lot."
"How easy is it to right solo (I'm 165lbs)".

VERY important to be able to right in ANY conditions, especially given that you might be out of sight of other sailors / motorboats etc, an upside-down boat is difficult to see. I would see this as being the MOST important factor in deciding on which boat to get, given the task of sailing solo often.
I`m 148lbs, sail a lightweight 16ft cat (105kg boat) with fairly short mast (7,36m / approx 24ft). Mast weighs 14kg. I can right the boat from turtle in any windstrength, mast is sealed, but I have to stand on the tips of the daggerboards to right it, which means that I`m not quite heavy enough, but I`ve capsized a lot & never had to be assisted.
I think you`d find yourself in the same situation with any of the F16 designs - the mast is longer than mine by 4ft / 1,2m, which is a lot, but is about the same weight, and the boats weigh much the same as mine, so you`ll have no trouble there being 17lbs heavier. From what I`ve seen in other posts the heavier 17ft boats will be near impossible for you to right on your own.
Hobie 16 is not really suitable for solo sailing, and can also be difficult to right solo at our weight range. I can`t right the Dart 18 solo, even with the waterbag.
In my opinion you`re limited to 16ft lightweight design boats due to your weight & intended use, I`m not trying to sell F16 or any other class, but it seems the most logical option for sailors of our weight, I`m sure the FX & I-17 are great boats, but not if you can`t sail them confidently knowing you can get home without help. They are more suited to heavier, bigger sailors who can solo-right them confidently.

Cheers
Steve