If you're getting at AQ3500D then a fully loaded fi btl would work. Just get a dual 1 ohm fully loaded sub and wire it up to 2 ohms. It'll be better on your electrical at 2 ohms than 1. That way, if you want another btl after you upgrade the electrical, you could use the same amp and wire it to 1 ohm with the two woofers. I'd go with either a btl, xl, or level 5..whichever is cheapest