First , I would say get a good 90 days worth of good riding time before going 2-up.The dynamics change quite a bit with a passenger. Pretty much any bike with 400cc will be fine for a rider/ passenger situation,unless you are going to be doing some extensive touring. With you being new at this, a smaller bike will be much easier to navigate when you first start carrying a passenger and will also be more recoverable. Remember, upgrading to another bike is normal so get the experience first and foremost. The safety of your passenger is a big deal, so be good at what you do before bringing in another. As far as mileage, if it has been well kept, I could deal with a bike that has up to 15,000, keeping in mind that I will probably upgrade next year anyway. Take care,Ride safe and God bless. Jon D.