Buying a Hsu Research Sub

Hi, I'm changing some of the parts of my system, included the sub. After reading a lot in the internet, I decided that an Hsu sub is very good and not much expensive, so I'm thingking of buying one of these.
The thing is I'm not convinced wich of thes two: STF-2 or STF-1. The difference in price is just $60.00, so I'd rather buy the bigger one, but I don't know if is too much for my system:
- Pioneer VSX-1018AH receiver
- Oppo DV-981 dvd/cd player
- PS3 for blu ray and games
- JBL ES30 fronts and ES25 center, ES20 rears
- in a 10x13 room

Do you think is better the STF-2 in case I change to a sligthy larger room? Is better to save the $60.00?

Next on my list will be the speakers, but for now I think they sound very good.

Thanks

Thanks, I think I would go that way.