I think the 810e does just fine with low tunings. I see a lot of low tuned bassists who use them, too. Anyway, I'd do the Ampeg/Peavey. The 1001RB is a very good pro-level head but the Goldline cabs are crap. And if you're going to skimp anywhere, don't skimp on the cab. Meh bass + meh amp + great cab = great tone. Great bass + great amp + meh cab = meh tone.
Ampeg Portaflex Club #1