The best? Who knows. Take your pick.
I wouldn't buy an Ampeg PF500 because of the issues they had, which I'm sure have been fixed by now, but all the units that had "issues" are still circulating. Apart from that, I don't think there is a bad amp on the market these days.
Amps I know and getting good reviews; TH500, TH530, Mesa D800, Genzler Magellan. . . plus what everyone else has suggested will also be good.
Cabs: I'd look at getting 2 112 neo cabs.
I'd recommend separates because you can upgrade more easily.