Hi Tammy:
Green beans need very very tall obelisks so the bottom width needs to support a minimum of 6' tall of obelisk. Ideally you would want them 8' tall. I have 4' obelisks for shorter climbing peas, and they have a 2.5 square foot area (4 legs). Yes, I plant two seeds at each leg. Just in case one doesn't grow!
Tomatoes all take different sized places. Indeterminate tomatoes: some hybrids, Romas - they can take a medium sized "regular" tomato cage and do well. Mine are about 2' around. Indeterminate tomatoes take up much more room. I use the largest cage I can find (4' tall) and have to stake them also (they get so full of fruit they fall over). 3' in diameter up top. Below them they take up less space and I will grow small items around them - bush beans, arrugula, you can probably do lettuces all summer?

Some peas are pole,some peas are bush habit. The seed packet should tell you. All of your tomatoes are indeterminate and will grow large. Even cherries so BIG cages for them all.

The Mr. Big peas you are planning on growing only grow to 4' tall.

Thanks a lot. That was loads of help. I never thought about planting under the tomatoes. I am hoping to get 4-- 4x8' raised beds built to plant these in.
Tammy