Sewing Machines aren't necessary for you to quilt, after all our ancestors were quilting long before sewing machines came along. However, they not only make the quilting experience a lot easier, but a lot more fun and rewarding. Almost all brands have made a machine for quilting; this means the machine has special quilting stitches and features for your quilt making projects.

Baby lock has quilting features on several of their machines. Also it comes with a walking foot that simplifies sewing the batting, quilt top and backing together. There are many decorative stitches for quilting too. It also gives you the capability to do free form quilting; this is when you decide on the design you want stitched on your quilt and do it with a free motion attachment.

Bernina is the only machine that has what is called an accufeed system that keeps your stitches uniform while doing free motion stitching. Another nice feature is the pivet feature, where the needle stays in the fabric and the pressure foot raises at the end of a stitch. This way you can turn your quilt while still keeping your hands on it at all times.
Singer makes a long arm industrial sewing/quilting machine, which will make quilting much easier, but most people who sew don't invest in industrial machines. They tend to be large and bulky and take up a lot of space.

Husqvarna Viking makes a long arm sewing machine that is great for quilting because it allows more room for maneuvering your large quilt while top stitching. When buying a sewing machine, be sure and check out several dealers before making your purchase. Buying the top of the line is well worth the cost if you do a lot of sewing. It will give you many years of happy sewing.