Linton's have specified 3 dB higher SPL (90 dB) while Polk's R700 are specified with the same SPL but come with two 8" woffer's so arguably could go 3 dB louder if feed with enough power (4x more power which you by the way don't have).
Both can pass without sub regarding response down to 40 Hz, but with two SVS SB-2000 you would have it all the way down to 20 Hz and it could go considerably louder (let's say 9/12 dB R700/Linton's) and without having to get considerably stronger power amplifier (they come with 500 W RMS inbuilt one's).
So you get 3 dB more with Linton's for same amount of power (+3 dB = 2x W) and that certainly won't make much of a difference. Interestingly Polk is giving away it's entry level PSW 10 sub's (which actually went well on Eren's measurements) on purchases over 500$ (one sub per one purchase).
The PSW 10 subwoofer features a 10" woofer in a vented front panel port enclosure to add deep bass excitement to your music or movie sound system.
www.polkaudio.com
But those are too small and week for you.
By the way you can get two SVS SB-2000 right now from Amazon (on sale 550$ a peace) for the price of single Polk R700 speaker.