I think it might be helpful to rent or borrow a couple of different cameras to take them out for a spin. To me, the way a camera feels and handles in your hands is important. You want something you feel comfortable using. I had lusted after a Mamiya RZ67 for a really long time, and was going to get one, then I rented one for a weekend and completely changed my mind about it. It weighed a ton! The nifty rotating back, and other features I liked, couldn't compensate for the weight.
Beyond that, I wouldn't make a hasty decision based on how much money you have in hand now. If there is a camera you really want, you're better off waiting til you can buy that one. Otherwise you might regret it, and that would end up costing you more in the long run. And you don't have to get a bunch of lenses right away. You can start out with one.