clayd,
The small twin LS2 100 is not a good choice unless staying stock. It is very limited/difficult to modify if more hp is wanted. Parts suck, intake port is very restrictive, cylinders are all cast iron meaning more difficult to port, stock pistons are cast not forged. Now the real problem is the crank and very few of us have the proper tools to rebuild it, rod top eyes are not drilled for oiling etc. I have done a couple of these and probably still have stuff floating around but its a bad choice unless you insist on it, yes it can be made fast but take Sofadrivers advice, the KX is modern and parts of good quality are availble, its water-cooled, modern day tuners know the engine so you have a choice of builders if you want more. With all that said I know if a couple people read this they will think I went off my rocker because they know I am a Yamaha guy. lol
Good luck and good on ya getting that little gal on the salt.