I'll second the EA recommendations - my CXL 112 is a phenomenally flexible and solid cabinet. It is my main cab and it's the only one I need for 95% of my gigs.
If I were to need additional volume, my first candidate would be EA's 2x10 cab. I've had very good experiences with my Acme 2x10 cab in the past, and I love the idea of a 2x10 that is more efficient.
Amp-wise, it seems like your best bets might be the EA iAmp 800, an Acoustic Image Focus, or a Walter Woods. All three are quite expensive, but they all seem to be almost universally hailed as the highest-quality and most flexible amps for DB and/or DB & BG doubling. Personally, I would go with the AI Focus, as my AI Clarus sounds great and is small, but it is a bit underpowered for some louder applications.
Hope this helps!