I'd stay away from the chinese 250's they look like a chinese ag bikes with a pitbike subframe stuck on to me and hear they death wobble at speed.....
I got an MSO sr and couldn't be happier with mine ...I got a pro as well but I'm tall like you and have found the SR more "rideable" and don't throw a leg over the pro as much these days .... if ya wanna race they are very competitive and they have THE best aftersales goin around and a dedicated race/freestyle team that are testing and developing the bikes constantly too keep ya at the pointy end of pitbike development .