Ok, that box is 1.5 cuft sealed. I can’t find a mounting depth measurement anywhere.
I’m a big fan of JL Audio. You could go with two 10W3V3s in that box (assuming the mounting depth is good) and it would kick ass.
https://www.woofersetc.com/c-23-sub...3-4-jl-audio-10-500-watt-4-ohm-subwoofer.html
With two of those you would wind up with a final load of 2 ohms. Personally I would probably look at a Zapco amp or maybe a JL. Something that does 800-1000w at 2 ohms would be about right.
This one looks nice.
https://www.woofersetc.com/c-3-ampl...co-monoblock-1650w-rms-class-d-amplifier.html
I use a Z-1KD which is a bit lower powered but a solid amp. With your two subs the Z-2KD might be a better option but it’s a lot more money.