I raced a 250 for a year and had a blast on it. I am oldish and heavyish and it was still a great learning experience. Last year I rode an SV and had an equally good time and enjoyed the bonus of some added speed over the 250 in the lightweight classes. I am quite happy with the SV and will stay on it again sports his year. I recently picked up 20 year old CBR and have been riding it for the last couple track days and am having A great time on it. I think all of those choices would be good although a MV legal SV would probably give you the most class choices that the bike could be competitive in.