A dual band ham antenna (like this: http://www.diamondantenna.net/nr770ha.html
) would get you pretty close.
How long a run of coax and what type? These things claim pretty wide bandwidth, but you'd still be just outside of it. You won't have the greatest match. But if your coax run is short, you could probably take the hit and be fine.
you can adjust the phasing coils and lengths slightly as well and I'm willing to be you could end up with a find match on GMRS and 2M. GMRS isn't very far outside the 70cm band. About 12mhz