My recollection is that Steve got a few cans of Bonta from Escalon, although I don't know the circumstances under which he was able to get them. Some foodservice companies that carry the Bonta products will sell to individuals but most don't. One that apparently does is Gordon Food Service (GFS) but they operate in only a few states, mostly in the mid-west (and Canada and Florida, I believe). PennMac has the Bontas on their product list (but not on their website) so you might want to call them, at 1-800-223-5928 (412-471-8330), and ask to speak with Rose, who is a member of the forum and deals frequently with our members. It may be that you will have to buy a case of #10 cans but it can't hurt to inquire as to whether you can get just one or a few cans. Some #10 cans are already sold individually at the PennMac website, at pennmac.com (under the Pizza Makers tab). PennMac also sells a lot of other pizza ingredients, so you may want to keep that in mind also if you need any other pizza items.
BTW, I use the 6-in-1s for deep-dish and found that if I drain the tomatoes for a while they will thicken up and be fine for use with the deep-dish.