First decide your budget and buy a machine that is in that budget. Then make a list of what you would like to have in a machine...however, if this is your first machine you may not know what would be nice to have. To me, the most important thing is to purchase a machine from a store that will provide support for you and does machine repairs. If you find a store that puts a lot of pressure on you to buy their machine, I'd look around at other stores too. I don't know where you live, but hopefully you'll be able to visit more than one shop.
Patchwork is just straight stitching so most machines nowadays can do that well. I find having a needle up/down function is great and I like having a foot pedal. If you plan on doing machine quilting, I'd get the largest throat area too...throat area is the space to the right of the needle. Different feet will come with the machine. Awalking foot is good to have too, but if it is not included in the purchase price, you may want to buy one. You'll be able to tryout sewing on a machine at a store, so do that too. Some shops only have a fabric that shows off their machine, so bring some quilting fabric to stitch on to see how the machine perfoms with quilting cotton.
My favorite machine is my Bernina, but they can be expensive. I bought my first Bernina used and it is my workhorse. I also like my Babylock. If you have a friend who sews, it would be nice if she could go with you. In the end, it is personal preference.