I would use grow bag compost - its cheaper and has nutrients to start them off in. They will still need tomato feed when they flower.

If you must have a commercial compost I would use a multi purpose compost with added John Innes...i think Westland do one.
I'm actually using levington grow bag compost in pots in the greenhouse to compare with my home made mix. Under identical conditions and pots, my tomatoes after 2 weeks are already much further advanced in the home made mix, which is purely peat based. That cannot be said for the levingtons which seems to have an aweful lot of fibrous stuff in it.

Much as it urks me to say, I have tried most composts and always have to smile when I see the Miracle Grow adverts on the telly, but although not the cheapest, certainly have been the most successful range of composts.