You should be fine with 10+ gal. containers. Many people (even I have tried it) do it with smaller containers. There is another current thread about dwarf tomatoes, where quite a few people use 5 gal. containers or grow bags and have reported good results.
Howdy. Whatcha growing (which varieties of tomatoes)?
It's gonna take an AWFUL lot of soil-less mix to fill those big containers. I've used a homemade recipe from Tapla (Al, over on the Soils and Compost thread), to accommodate the need for large amounts of container mix. It saved me a lot of $$$$. I filled ~sixty 6.5 and 5.0 gallon buckets.
So, I'll need to know the scale of what your container tomato patch will be, and have an idea of the size you expect your plants will be, e.g., tiny cherries, tangerine size patio?, gynormous beefsteaks?