I would consider a CX4 Storm with all metal trigger parts installed. Other than a comp or a suppressor there would be nothing else to buy. I would have suggested a CZ Scorpian but the largest mags I have seen for it are only 20 rounds. If there are higher capacity mags then the Scorpian would be head of the pack.
I like reliability, drama free and given the age of the body I have the above two rate higher than the AR platform design. Fun trumps trophies for me now.
Take Care
Bob
ps those two with a good holographic sight.