Agree with SEA... check out the MAA Manitoba Airsoft Assoc.
another thing you may want to try is getting in touch with Ambush Anonymous airsoft... they have a small speedball type field with bunkers, buildings, old cars and washers and dryers, Tires and wood structures..
small field and thay don't care how old you are as long as you act professionally and abide by the rules (which it sounds like you do) so check that out..
I know they have an 8 hour scrim next saturday first 4 hours are springers (under 300 fps) next 4 are anything under 400 FPS... they have a good CQB field...
on one note on your field. I have derived that you are outside the parimeter. so the City laws about discharging a weapon (be it real steel or Airsoft) won't apply...
Re permits outside the city well your land have at er.
not knowing where you are in MB just make sure no stray pellets hit a neighbours car or windows or the cash you save to buy the Broxxa will be spent replacing glass...
also check with your insurance... if you dig a hole and a friend falls in it and breaks their arm / Leg or worse neck are you liable for that... can they sue..
lots to look at
but I do as (Diamond SEA) stated STRONGLY encourage you to wander over to the Manitoba Airsoft Association for sure
and perhaps check out the action at Ambush Anon Airsoft... Bring your friends and have a blast