If you want the best bullpup and you have that figure to spend then there is only one to go for, Real Sword type 97/97b, run on any stanag mag, 97b has slightly faster ROF courtesy of a higher speed motor than the 97, build quality is, without any question or argument the best out there, I got mine from airsoft world, sign up for the 'new shopper' thingy and you'll get an email about 10 minutes later with a discount code which brought mine under the figure you've got
This is mine, have changed the flash hider for the little suppressor and it's got an e mag in for you to see, range is simply stupid, genuinely out ranges pretty much anything else (not like most people think they're rifle shoots 70m)