Not sure if the UTG M324 would be compatible, but that might be a good try. Otherwise, maybe search around a look for a stock trigger housing just for now, but it's going to need a new assembly regardless.
I've currently already got a Guarder Reinforced Bolt Handle$102 - First Factory/PSS2 Teflon Cylinder
$25 - First Factory/PSS2 Cylinder Head
$17 - PDI Ezy 9mm Vacuum Spring Guide
$54.50 - PDI Vacuum Piston
$36-$59 Gaurder/PSS2 Reinforced Bolt Handle of Choice
$(Depends on the Spring) New Spring! My CA 300% spring (same as yours I beleive) isnt very good but like I said before... for those with a tight budget, it gets the job done.