Ampeg VH-150 question

[fredCRUSADE]

I'm dumb and this seems like the best place to ask this question...

I have an Ampeg VH-150 and I'm in the market for a new cab. Right now I'm using a 16 ohm mono Marshall 4x12 and it's not really cutting it. It sounds good but it sounds waaaay better through my friends 16 ohm mono Soldano 4x12. The question is... What is the ideal way to connect this amp to a cabinet. Should I use one of the speaker outs into an 8 ohm cab or use both speaker outs into a stereo cab (at 4 or 8 ohms?)? I just want it to be as loud and heavy as possible. Here's a picture.