@Jonathan Greene brings up a really good point as far as the dynamic goes. It's possible you have all discussed this already but its important to get it all squared away before purchasing anything. How are you dividing cash flow? Who's making repair decisions? How are you deciding when to sell or settle disputes etc etc. Important to do that before anything is bought.
As far as choosing a market goes: Go to meetups and meet people. Talk to them and see where they invest and see if any of those markets spark your interest. You're never going to find the perfect market with super low prices but extremely high growth and rents where values are going to quadruple etc etc. Find a good cash flow market, do your research and pull the trigger. Don't get stuck in the analysis. Talk to people and if anything, try to pick a market you wouldn't mind visiting since it is highly recommended to go there at least once. Hope this helps.