Some of the larger Kahrs might work well. The smallest series probably not, but they have 3-4 different sizes. If I wanted to carry a full size gun my T9 would be just about the easiest of those i have handled.
There are the conversions of Glock compacts and full size to use the sub-compact slides and barrels. Always thought they were interesting and my fit your bill if you want a full size grip with a short barrel. The barrel length is never a concealment problem for me though.
Would be interesting if Kahr made a full size grip with a short barrel as slim as they are.
Of course, I think Beretta already has a few guns with grips that seem large for the barrel length. Not sure on their exact dimensions, only basing that comment on memory of their appearance.
The only good way to conceal while active for me is a fanny pack. I used a runners pack with a little water bottle for a while. It had better support than most fanny packs so the gun didn't bounce as much and didn't look quite as dorky. Of course, I was using it while running.