That's a very tight budget. I would run a 10mm SuperCub from Redline, but that's going to cost you into the $6k range I'm sure.
$3,000 on chassis could be doable, if you get a package deal on shocks.
I'd run a +8 swingarm and +1 forward a-arms.
If you want to be competitive or beat all your competition, you may have to open your monies a little more.
Trust me..Been there, done that a lot of times.