Hi Joe, welcome to the forum!
I have few questions to add to what
@STRONGBADF1 asked.
Are you keeping the two VTF1s? Do you have any placement issues?
You can get four RSL 10s Speedwoofers at $399.00 each and be under your $2000.00 budget for one sub. If you add the wireless system, an extra $50.00 each, you'll be near that $2000.00 budget.
The 10s will play down to 20Hz.
https://rslspeakers.com/speedwoofer10s/