Well, unless you are going to buy a full contingent of mags, and a chest rig of somekind for them to use, you should go with whatever your current platform is.
That way you can lend off a couple of mags and an old or unused rig and they are good to go.
I had a brother out to Rampant Lion in muskoka this past weekend.
He used a Kraken AK and a Chicom chest rig, with a few mags borrowed from other players.
Worked out really well.