Nick, I'm not sure how large your room is but in a medium size room I think you will see the STF-2 or any decent sub make a big contribution to watching movies and music.
If it was me I would get the SFT-2 at the great price they are offering, then down the road when finances permit, you can always upgrade or even use two subs.

A computer once beat me at chess, but it was no match for me at kick boxing.