Its more about install and enclosure at the 2-3K level. Sounds like you have the gear, wire may be a bit lacking but hey... go for it. Wire is cheep and for Sa's anything tuned 32-35hz in 4 ft3 net with sufficient port ought to satisfy. I would have chosen Sa Classics and went with something in the 2-3k range even at 1 ohm. I normally wire lower so .5 is what my amp sees nominally because I live a little dangerously. Screw those Rp amps... I'd grab a Skv minimum and probably a 2500 for a pair of classics. Then address your "0 guage" and "big 3"... electrical never ends... lol. I supported a 4K amp with a 250A alt and a severe case of excessive interconnect. I actually could clamp 4200+ with a 4K amp in the 3K class. Tuning with cabin in mind and impedances let me dial it into an automatic 152+. Clamping right at 3K actually was more output than the 4K+ numbers. 150lb of deadener, trial and error in positioning and staging with a few custom additions worked out.
Its a steep learning curve.