I carry a Busse FB EDC. The most carried and the largest I can get away with is an older straight handled Badger Attack. 4 1/2 or 5" blade IIRC. I'm wearing it, just don't have a ruler handy. The others are a Mean Street and Active duty, both smaller.
When I say the largest I can get away with concerns comfort AND ease of concealment. With our CCW laws I can carry a Battle Mistress if I wanted and could conceal it. The comfort level would be next to zero though. LOL It's on my belt for 12/14 hrs/day so comfort is about my #1 priority.
If you want 'tactical', the Mean Street would be a good choice. The blade shape is more of a SD thing than the BA or AD. The Swamp Rat Bandicoot is on the same order as the MS and there are a few that were made from INFI (INFIcoots), that were done due to a mix up at the shop. About twice the cost of a regular coot, but still way below the cost of a similar Busse. They pop up now and then on the exchange.
As far as strength goes, and this is entirely subjective on my part, I also carry a large Classic Sebbie so I don't freak out the sheeple pulling a FB that they didn't even know was there. The blade of the Sebbie and the Active Duty are almost identical in shape/length and whatever. You can lay one on top of the other and they look like one. The AD is slightly thicker, but not by a lot. The Sebbie is no slouch in terms of anything, but still, the AD just feels like it would handle more stress and strain. Can't back that up with any sort of hard facts, it's just the way it feels to me. Could be bias, the Sebbie is the only folder I own, but I'm just not wild about knives designed to break in the middle, no matter how well made.
Rob