You can use a dual band antenna if your running a base station, but if you run a repeater, you should consider separate antennas, as you would have to be very careful. I don't do much VHF, but I do have a workman UV200 in storage. for the repeater we have also run the Comet 712. These fiber glass antennas flex a lot in gale force winds, need additional sealant or heat shrink around middle. If you are single story, get yourself a 20' section of pole 2" pole and a house bracket, some even have the ability to tilt out for service. you can mount another 10' to that for about 30' without spending too much.
What do you have for antenna height? Obstructions? In most applications the height of antenna is most important. using a ground plane I assume a Mag mount? Although not ideal, it could get you started. Tell us more about your site.