I have no experience of vertical growing Mart, but here are one or two ideas.
For compost I would not use any soil as it holds less nutrients than composts and you need as much goodness as possible. Worm compost would be superb. Composts also hold more moisture than soil so growing in top quality compost is more productive and easier where volume and weight are restricted..
Salads will surely be the most worthwhile vegetable, all raised as plants first. Also bush tomatoes, nasturtium, chard and spinach.
Keep us posted!