If you are set on the dual LPR setup you will need a fully custom switch. A standard switch in my mind cannot be modded to do what you want it too.
If you want to go the low tech route rig two switches to the trigger system. You will need to cap one barb hole on each switch. This will allow you to operate the LPRs at different pressures.
Also pressure of the switch should have no noticable effect on trigger tension. Your timing will be more of a hassle though. If you really want to make your gun faster to shoot pickup a nice adjustable 2 finger frame with stops and a tension control if you can find one. Then a nice short switch, BOMBs and quick switches are very nice. The bomb is just a little faster IMHO. A set of good quality QEVs and a nice smooth ram will make a heck of a difference. To top this all off you will want a dependable LPR though.