My wife grows lots of tomatoes and cans her own sauce.
A food mill is a must for getting rid of the seeds. It also purees very well, leaving a little texture for a rustic sauce, and you could use it for vegetable purees instead of a food processor. This Sunbeam 2-Quart Food Mill comes with three stainless steel blades and is very reasonably priced.
Sunbeam 2-quart Food Mill
Where to buy (buying from this supplier supports this website):
Meathead, BBQ Hall of Famer - Founder and publisher of AmazingRibs.com, Meathead is known as the site's Hedonism Evangelist and BBQ Whisperer. He is also the author of the New York Times Best Seller "Meathead, The Science of Great Barbecue and Grilling", named one of the "100 Best Cookbooks of All Time" by Southern Living.