What frames would you suggest?

I have tried to use an old impulse frame..but it just required too much work to fit correctly and was way too far back.

My real problems are the mounting of the mpa3 and the 3way fitting.

By and large I'd like something nice and cheap for my first run, as I dont want to demolish a nice chimera frame (though I'd likely mount the lpr on the foregrip, so I don't know how much I'd have to)

Any suggestions would be peachy.