Johnnies might have some good alternatives given that they are geared toward small farmers. (Marmond? I have not tried this; Diana have you?)
Tunnels are popular for tomatoes for small farmers but they tend to have more than one tunnel and use one or more just for tomatoes. They did a survey of Kansas farmers using tunnels and some were starting tomatoes 4-6 weeks earlier than in the field so there's definitely a benefit.
I really should start shopping Johnny's for seeds because no one else has the filters they do including greenhouse/tunnel rating.
Cauralina looks like a good candidate for a dual purpose tomato for the tunnel. Johnny's is very proud of them at almost a dollar a seed ($13.75 for 15) but if I could grow 15 plants in one row in the tunnel and get 2-3 loads of sauce plus a few to snack on, that would work.
Getting enough at one time from an indeterminate for a canner load is another story. Cauralina are 8-14 oz so at 8 oz, two per lb and I need 30-42 lbs which is 60-84 tomatoes? (Pozzano are 4-6 oz - if 4 oz, four tomatoes per lb or 140-168 fruits - insane)
So for all you tomato sauce/juice makers; Does 30-40 lbs or 60-80 or more fruits seem right for a canner load? How do you store tomatoes until you have enough for a load? Peel and freeze?