If built carefully and light the Little Cap is not a bad flyer. The ST .75 will do okay but it won't have the kind of performance I think one would expect of this type of model. The ST .90 would be a better choice if ur going with ST's, IMO. Mine has an OS .91 4S on it and while it has good performance, it doesn't have the vertical I would like.

BTW, start with the CG at the forward end of the envelope and move it back a little at a time. The Little Cap is sensitive to rearward CG and will develop a nasty tip stall and snap if it's too far rearward.