Yet another suggestion -- keep the Nexstar/FXi combo & put it on floats -- it is a very nice looking model & it would make a great float plane (remove the AFS stuff to save weight).

Buy a TT .46 Pro & put it in whatever your next choice is. If you buy a 4*40, be be sure to skin the wings with 1/16 balsa sheet up to the mainspar (top & bottom). The stock wing is too flexible.

Don't buy a .46 LA & put it in the Nexstar -- it will be a serious pig.