best subs to pair up with rf t20001bd

[1loudgagt1]

right now i have 2 rf t1 12's sealed wired to 1 ohm on my t20001bd. this spring i plan on upgrading my setup to a ported box with better subs. what would be the best subs for my amp.

rms at 2 ohm - 2350

rms at 1 ohm - 2266

these numbers are birthsheet numbers. other problem is the box could only be 2.25 cubes for each sub to keep my false floor and panels the same. box is going into a 03 grand am.

all input will be appreciated - thanks