I am no expert, but I believe a general purpose boat trailer is designed for a v hull. where a MC trailer has bunks that are near flat in the rear. Plus you need depth in the center of trailer for the tracking fins, rudder, prop. And the prop guard built into trailer.
here is a MC trailer cheap. not sure how far it is from you. Usually MC trailers are $2k to 4k used. Not sure if this one will fit a 90s model prostar 190.
Trailer - $795 (Carlisle, Iowa)
http://desmoines.craigslist.org/boa/2356130964.html