yes. there are several common platforms that are used around 150mph here. Funjet-type platforms have been clocked at 180+ mph, and there are other wing-based platforms used at speeds like this, maybe something from Ritewing? This is within the electric category. Looking at nitroplanes, you'll find some are 230-400 mph. There is a group here for nitro-powered planes.
lol. no, i don't know of anything like that. you'd have to build it. Maybe $25k - $40k in R&D. 6-8 months. Probably more, if you're asking this question ;-) Actually, it is probably more either way.
The fastest path is to look at gas powered helicopters, I suspect, given your new requirements.