yeah. The only way to get that dual 2 ohm version to work with that amp would be to wire it to 4 ohms only giving it 300 RMS. If I were you, I'd get the dual 4 ohm version of the Type R if you want to use that amp, then wire it to two ohms.
and I'd say about 750 RMS is the max before you start having major light dimming and whatnot. Before buying an alternator, make sure you've done the Big 3 upgrade