^ I'm not too well up on cabs either, to be honest- I just know that as far as I was concerned, the Marshall cabs didn't sound all that great with the engls I tried. Now, to be honest, I'm not sure if they were the vintage-30 loaded Marshall cabs or not, but the ones I tried definitely sounded a little "flat" or something. Just wasn't a good match, IMO (though my idea of good tone could be vastly different to yours).
The engl vintage-30 loaded cabs sound great with engls (obviously enough), but the 2x12 is about £400- you could get my laney 4x12 or th framus one for the same price or less. And the engl vintage 4x12 is about £600.
I'm a bit wary of giving recommendations based on the few cabs that I have tried engls with, to be honest- I'd just be wary of Marshall cabs unless you can somehow get to try a screamer with a Marshall cab and like it.