Underseat: ARC 4050 or SS RUB500.4 or what?

[FUTURISTiC]

What's up party people?

I need to power (2) 2006 Mitsubishi Evolution factory door speakers with an underseat amp. I also need this amp to power a shallow mount 8" like the Earthquake SWS-8X. Head unit is a Kenwood KDC-X994 if that make any difference to anyone.

Dimensionally, I'm limited to less than 3"H x 8.5"W x 15"L

Someone has recommended the ARC 4050, at $350-ish.

I'm looking for:

efficient (not upgrading electrical)

COOL-RUNNING (under a Recaro seat, not trying to put something under there that you can cook eggs on!)

Powerful for it's size (enough to power the SWS-8X in 3"H x 8.5"W x 16"L enclosure + factory doors)

Bargain

I've searched, and see recommendations for things like Soundstream RUB500.4 ($150! ), Alpine PDX 4x100 ($360), etc. Considering the criteria above,I'm looking for the best amp for the money that will do the job. I'm really not trying to spend $350 on the amp and I'm a little worried about the ARC 4050 running hot, as the person that recommended them is a ZED fan.

I don't want componentry bragging rights, and I don't want to pay for something that is going to be overkill for my small underseat box. I want it to be able to handle the crossover requirement for the sub + factory door speakers.

Sorry to be a noob and ask, but I really need some expert advice. My knowledge is so limited that I'd have to search to confirm that the 2 4ohm rear channels would be bridged to 2ohms for the sub. I've had friends with everything under the sun back in the day (early 90's)... Broke-ass high school buddies with 2 kicker 10's plus a punch amp, and buddies with 4 JL 10's and PP Art amps, but I was more broke than even my most-broke friends, and never made the money to buy a sub/amp before getting into speed and forgetting about subs.

[dolarbilz]

Ill take Alpine and arc audio.wont touch soundstream.bad experince with rubicons. Twice!