Heckler & Koch
If it is durability, accuracy, feel, balance, and value, I would suggest spending the money on an HK. The full size or compact are very good weapons, and since you are looking to carry, go with a used one. They are fairly well priced on Gunbroker.com
I have had several USP's...
Not exactly a build question, but more of a price and availability thing. I have built several guns, including a HK94, 91, AK47, 74, ect..., but I have not built one of these.
About how much money are we talking about to complete one? My 94 was around 1,000.00 when I built the parts for it.