sauce with local tomatoes
from my Okanagan point-of-view - ask your farmer market person for a "sauce" tomato - Roma is a classic and there are many others (see below for link) - and the Romas are quite different in shape ... they are longer, kind of more like what we think of for a bell pepper shape. In the Ok valley, the size ranges, so some are small (like your thumb) and some are much bigger. The reason that we choose those is that they are a less wet tomato - you wouldn't really use them for salad as they are drier. I suppose they are sauce tomatoes cuz they thicken up sooner when you cook them
to learn more about what you might find at your farm market / farmgate stand - have a look at West Coast Seeds and search for "tomato" (this company sells for the Pac NW growing climate) - those tomato photos look good!
i assume you know how to remove the skin - that will be somewhere here on CH.
tomatoes freeze well - tho it takes up space - so maybe make the sauce then cool it and freeze in small freezer containers / ziploc type bags.
you'd have to ask over on home cooking chow-board for more input - however my understanding is that seasonings become more pronounced after freezing - so go easy on the garlic, pepper/s, herbs, salt.
re: Georgia Strait
Agree re checking out your local FM to find out about/try varieties. It's pretty rare to find specific options (beyond roma, beefsteak and one or two others) at most greengrocers in my hood. The tomatoes at the FM are often what is known as heirloom varieties so expect to pay top dollar.
There are two markets today: Kits and the new test market in Mount Pleasant. For hours and locations of all the Vancouver markets, see here: http://www.eatlocal.org/markets.html