I had a GSG M9 replica from JBBG, it was actually great for £20. Just never bother disassembling springers or anything cos I've broken like four doing that :/
The G21 is probably the best of the bunch. The P38 is an historic pistol, an aspect of airsoft which interests many, so it's more about 'an interest' than about looking cool, which is a good point for you to argue.