Well I tried going from the vague specs polk has on their site but they must not be accurate or something winISD doesn't like them. so you will just have to go by the boxes they have suggested. Here Polk Audio - Car & Marine Audio Speakers
. looks like you want to shoot for a sealed box between 1.0 - .66 cf who knows what would be optimal without the specs...
Its pretty dumb that they do not give you the displacement of the motor structure, its pretty important to know how much the sub takes away from the final volume of the box.
I would say PG is of better quality then the crunch. really you can get away with almost any amp that puts out plenty of power. its best to exceed the RMS power rating for the sub. that way you can be sure your amp wont get "winded" and clip the signal. subs aren't sensitive to having clean power as mids and highs are.
Toreador Red 05' FX4
4.0 4x4 A/Tran Ext.Cab Daily Driver. Nomads, BFG M/T's
Alpine 9857, JBL MS-8 DSP, US Acoustics 2x80w & 2x100w, Vifa 1" XT25 Dual Ring Radiator Tweeters 3k+ 24db slope, Dayton Audio 7" RS180-4 Mid-woofers 100Hz-3k 24db slope, 500w rms Kenwood Class-D Mono - JBL 10" GTO1014 Sealed. 100Hz- 12db slope