There are some avrs that have two separately adjustable (for level and delay) subwoofer pre-outs, but as shadyj mentions those are generally at the upper ranges of an avr brand's offerings. Audyssey XT32/SubEQ equipped avrs (generally Marantz & Denon) have the two adjustable subwoofer outputs, and I believe Yamaha and Pioneer have a few models as well. Many avrs indicating ".2" sub pre-outs merely have an internal splitter, or you can add an external splitter to a ".1" like shady says.
The matching up between speakers and sub is largely in the care you take and the settings in the avr to help out. Too bad you can't swing the SVS instead of the Polk but $200 is on the low side for a sub. What volume room does your sub need to fill?
Banana plugs do not improve audio, poorly installed ones could even detract. They're about convenience, on the backs of many avrs they're easier to use rather than inserting bare wire ends and tightening down posts, and are especially handy if you're moving things about frequently or changing gear frequently. A good solid bare wire end connection is just fine, tho.
I'd do some reading at this site about speaker wire and use the included table to select gauge/length.
http://roger-russell.com/wire/wire.htm or an Audioholics article on speaker wire here
http://www.audioholics.com/audio-video-cables/speaker-cable-gauge
