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In terms of your choice of pistols, the KWA PTP series are very good, however, mag availability is an issue. Also, as they are KWA, they don't have trademarks at all which is fine for some but others like those in a pistol.
If you want reliability and durability, stay away from WE. They are notorious for using pot metal and bad quality control. Sure it's full metal and cheap but in airsoft you really do get what you pay for. Anyone here will tell you TM is the way to go for quality internals. It's not hard to buy a TM and acquire a metal slide for it if you want full metal. Look at some of the race guns on these boards, those are all built off TMs and customized to the tits.