You'll never get consistently good designs with a system that "scans" in a picture and converts it. That is called autodigitizing, and it doesn't work very well even with high priced systems. As Lori S recommended, pick your machine first and then pick the digitizing software independently. All the quality systems work with basically all the machines so you aren't stuck with just one brand. Also realize that making good embroidery designs takes practice and effort - it is not something that happens the first time you try. I always recommend new embroiderers get a good machine and buy some good designs to see how they sew out. When you realize what makes a good design (underlay, stitch angles, compensation) you'll know what to do to make your own designs well. There are so many good designs out there for small amount of money that many people who start out thinking they're going to do their own designs decide it just isn't worth it. Then again, some people really get into it because it's fun (like me!).
Note that I do have a small embroidery business and do digitizing for others, so I really do know what is involved. As for specific machines, pick the one you'll get the most support for. For most people that means a good local dealer. A good one offers training, both initial and continuing. They'll be there to answer your basic questions, and they'll get a machine repaired quickly. A good dealer is worth their weight in gold!
Pam