Hello Trish. First I would go shopping
for jars, imagining what size you'd prefer to have/use. Frankly, I cannot see using any jar larger than a pint. What you (okay, *me*) want is to be able to can/preserve meats. Quite frankly, sauces and canned goods from the grocery store are practical and economical -- why go to the expense and time of preparing my own?
So, think about how much meat you eat in each meal and that's the size jars you'll want to use. Next, find a pressure cooker that will accommodate that size jars -- four at a time minimum.
As an aside, mine is a 3 liter foreign unit and as per a suggestion on SSCA I bought a spare rubber gasket
at time of purchase
. Mine is small (no handle) and fits four of the 1 cup wide mouth jars or 7 of the smaller jelly jars (.5 cup) at a time. My unit will not fit the taller 1 cup jars. Oops!
Just don't think of the pressure cooker as canning your entire scrumptious home-made dinner. Instead, add the fillers (rice, potatoes, noodles, spaghetti, e.g.) from your dry goods locker. My little 1/2 cup jar of prepared sausage (sliced and precooked with ground beef as the filler) with a can of tomato paste, an onion, garlic, and perhaps a fresh tomato too... well, that's a lovely spaghetti or rigatoni and sauce meal and takes very little space to store. Plus, it's delicious, even if I do say so myself.
For a year's worth of meals
(and I'm based here in the US with stores relatively easy to get to -- sort of!) I have about 6 to 8 dozen jars on hand. They take up a lot of locker space but it's so worth it to have the freedom to decide at 4:30 in the afternoon that some pork salad would taste great about now -- and be eating same inside of 15 minutes.
My canning is for convenience and quality of contents versus saving money
so I have perhaps a different outlook than others. For you and yours, the canner that fits 4 or 5 pint jars would be the one I'd buy and use.
Aside: Wide mouth 1 cup jars can be used to make lasagne and it will stick together/come out of the jar intact.