unfortunatly the majority of bikes have the same ride height as the MSO. you could change the MSO to a 10" rear 12" front but that only shaves a small ammount of ride height.
the other option is to go with a honda crf50. then throw an 88 big bore kit on it and some other things and it will be rippin then, but this is also probably a good 3.5k for something like this and probably alot more in the future. (people have been known to spend alot, one dude i know has spent over 17k on his, its insane) another option you may want to look into would be the honda crf70. the ride height may be in between the crf50 and a MSO X6R.
Cheers, Tony.