Those Aventon frames are indeed pretty cool: lightweight and affordable. I don't especially care for the looks of them, but that's a personal thing. I've never ridden one, but my friend has one and loves it.

I think you can meet your goal of $1000 for the complete bike if you shop around for sale/clearance items or buy used. Check Velomine; they have the best prices going on a lot of items.

I'm not aware of an affordable track frame with a press-fit BB. Most still have English threads. Square taper spindles remain very popular for FG bikes, but there are some good external cup/hollow spindle offerings as well. (Sugino 75 comes in that configuration now--outstanding quality but very expensive... or SRAM Omnium--also very good, and much cheaper)