As for a BFM Jack15, you'd likely never need a second cab. The tone profile is a bit different, although the 15 looks the smoothest of the bunch, and the benefits of horn-loading makes it just plain LOUD. You'd find your amp idling along, barely having to work for the small gigs you describe. At larger gigs, people will be wondering how in the hell all that sound is coming out of one box. Horn loading also filters out a lot of distortion. Not distortion as an effect, but the distortion we've all come to expect as part of the sound created by "regular" speakers.