Tag - I like the idea of 357sig (I like 38 Super as well, but it's more difficult to find compact guns chambered in it, and 357sig brings a little more to the table anyway)...
I'm trying to decide if it's worth it to buy a P2000/LEM in .40 and a barrel in .357Sig (I like the HK), or buy a .357sig conversion for my Sig 229/M11A1 (it'll be a little bit less than the HK/barrel, but I think the trigger will take more work to master on the Sig)...or buy a G32, or G32 upper half for one of my existing Glock frames.
They're all within $50 give or take...the HK would be within $100, buying a used HK and then the barrel off ebay or gunbroker..I'm just not sure which would be the best way to go. Both HK and Sig put a lot of engineering and thought into their .40 and 357 guns, but the Glock is pretty ubiquitous...