I have a Bernina 650. It is a stand alone embroidery machine. I don't know if they make them anymore. It uses the PES format that only allows me to do a motif of 4" or smaller. Brother held the original patent. I prefer the seperate machine so that I can have it running while I am sewing on the other machine. Most of the major companies make an embroidery machine of some kind. The machine is just the beginning. I have several thousand dollars tied up in software, a Magic Box and even downloaded software. Then there is the thread, stabilizers, different hoops etc. etc. I have used it a lot. I made several quilts with it including the one currently on my bed and my daughter's wedding quilt to name a few. It is great for personalizing gifts etc.
I saw one for sale in Walmart just last week. I don't know what kind of designs you could purchase for it. They all come with a certain amount of built in patterns, alphabets etc.