M90 or M100 will bring you down to what you need. IMO 350 is unnessecary since CQB distances are so short that a velocity change will only affect the time it takes the BB to exit the barrel and hit someone by milliseconds if not less than that.
330 is probably a safer bet (since a lot of fields use that as the limit) and as such the M90 is probably a better spring to go with. Remember FPS limits are just that a limit not a goal.
ಠ_ಠLess QQ more Pew Pew
READY TO >> RACE