My son has all three of those GBBs.
The KSC USP .45 is the most accurate. If you plan on using top gas (propane) you will need to get a metal slide and barrel. My son got 4000 rounds on propane with the plastic slide before it broke. Now he has over 7000.
The KJW P226 and WE 1911 are about the same as far as accuracy goes. They both look very real, both cycle well and he has put about 2500 rounds through both of them with no problems.
Spend the money and get the KSC USP with a metal slide and barrel or get the KJW P226. That is my opinion
