Hello Kelvin, and welcome to the forum.
I will second Frank Schifano's suggestion to go to keh.com (Dead Link Removed) to see what's available, and at what prices. You'll find very good used equipment, there, at very good prices. Their camera condition rating system is quite conservative, so you're likely to get items that are in great shape. Other suggestions, here, are also very good as an introduction to the format.
The other thing to do, and most important, is to find some stores in your area, in Arizona, that carry medium format outfits -- new and used. Talk with the sales people and actually handle the cameras/lenses, to get a sense of how they feel. Think about what your most likely uses/approaches will potentially be for a medium format camera, and, whether you'll want to build/expand a system on it. You mentioned you're looking to do portraits; you've got some great choices and options, ahead of you.
Good luck, and let us know what you end up with.