I would summ up thus, but I must declare that in the past I have owned the following

Dart 18
Hurricane 5.9 - 20 foot big 2 up cat with a kite
Inter 17 (slightly slower version oif the N17)
F16 (Current boat).

If you want to sail 2 up ONLY; get the biggest boat you can find; I assume US based so a Nacra 20 is the boat for you

If you mainly want to sail single handed, but want to sail 2 up sometimes (or visa versa) and want flexability of design, sail cut and setup, and don't mid doing some fiddling yourself once you learn to sail the boat soyou can have things where YOU want them; get an F16 of some sort and spec the sails "for the larget person" and so you get max power


If you want to sail only single handed then you really have 3 choices

1, F16 again (with the option to have sails cut for you
2, A class, again you have sails cut for you,l but NO Spi
3, F17, This boat is a one design boat, and you should be able to pull it around and right it with your weight.



I'm fairly light (70ish) kg and found I could not cart the Inter 17 around, or get it back most times from capsize, but you should have no problems with this.


If you have a fleet of one type close; it might be a good place to start.


My view, buy an F16 as you have the most options and a Spi!