Welcome to the board! You're getting some great advice.
I was where you are about a year ago and I ended up deciding to buy a mid arm after doing my due diligence. A long arm just wasn't right for me for a number of reasons once I really got into it. That's why each of us needs to really get hand-on with a lot of machines and talk to a lot of different dealers and, as you say you are going to a big show in May I think? That is the best idea. Until then, renting time and working away at the quilts you have is a great idea, too.
Have fun and keep researching. It sounds like you are doing well working on the rented long arms, so you should do great when you get your own.
Watson