I love veggie burgers and veggie hot dogs - I used to have them when I visited a friend who is a Seventh Day Adventist - I think (but am not 100% sure) they do not eat meat at all. If I could get them here, I'd never eat meat dogs and burgers ever again.
Yeah, if they are strict 7th Days they are vegan (I have also known 7th days who aren't as strict and are just vegetarian or eat meat, though).
When I became vegetarian about 15 years ago there was no calcium fortified OJ (I believe it was actually illegal!). Where I lived no grocery stores carried soya or meat substitutes at all but lucky for me there was a 7th day community near where I lived and they had a (really small) variety/grocery store which carried those things (not OJ but other stuff) so it made it so much easier to become vegetarian.