The subs won't be pre-installed though. You can match any sub with those systems. A much better sub for the money.
Unless you aren't buying a sub - but choosing which one to use.
Looking at the stats of these two subs, I'd give the edge to the Klipsch. It has a slightly bigger cabinet, and maybe a touch more powerful amp (I'm more confident in the cabinet size spec than amp power ratings). Bigger means potentially lower tuning, and for home theater use you want your sub to go as low as possible. For the record, the Infinity claims it is down 3db at 27hz - and the Klipsch at 28hz. The Klipsch apparently rolls off at 120, and the Infinity at 150. I'm more inclined to think the Klipsch may have the slight edge for HT use. Since you'll be running your crossover at 80hz max - it really doesn't matter what either sub does above 80.
That said - I had a sub that published itself as rolling off at about 24hz - but for the life of me I could not get a signal out of it until 27hz. Moving to an ID sub (the MFW-15 by AV123) - I can attest wholeheartedly that the material in movies playing below 25hz is VERY IMPORTANT. I am now down to 17hz in-room - and seems to have added a whole new dimension to the experience.
You won't find many home theater enthusiasts raving about a subwoofer that rolls off above 20hz. In my experience - the "wow" factor kicks in at 20hz.
Next time I buy a sub - I'll shoot for sub-15hz output

Seaton Submersive - I'm lookin' at you!