Without sounding like a sales rep for Alex, I'd have a look at the [url="http://barefacedbass.com/product-range/super-twelve.htm"]Barefaced super 12[/url] or some of his other cabs.
You'll be hard pushed to find one 2nd hand tho.
Other cabs I'd recommend are any decent 2x10s or 2x12s from Markbass, Genz Benz, Bergantino, GK, TC Electronic, etc.
My best advice is to get to a good bass stockist & try loads out (Bass Direct, the Bass Gallery or the Bass Merchant are but a few that come to mind).
Most of all, have fun trying different options.