i think you are all over complicating this and going into one. let someone organise it and just make it a casual rideout where a roughly equal number of girls and lads turn up and just go for the offroading. if anyone like anyone, then email them.
maybe you could have a "no chatting up" rule whilst everyones out together.
i used to be painfully shy and crap with women.im now married and much more happy and confident. meeting people is painfull and hard but as they say, "if you dont ask, you dont get"…
just do it, youll all have a fun day out…