EQ 6 is the one I would choose. I haven't upgraded to 6 because I can't afford it; no job at the moment. I've been using EQ5 for several years. It's easy to learn and you can do a lot with it.
That's my admittedly biased preference. There are several programs available. If you belong to a quilt guild, you might ask some of the members there to let you try the software, they use on their computer or at least watch over their shoulder. Software is a non returnable item. So if you can try before you buy, so much the better.