Have you checked out Espoma products?I was considering using Miracle Grow on my mother plant peppers because it will encourage growth without blossoms/fruits. Before I buy some I figured I would put it out there what I am doing incase someone just happens to know a better product to achieve strictly vegetative growth in peppers. Regular Miracle Grow will make beautify plants with not fruits. I assume its the same way with Tomatoes too.
I am guessing a pure Nitrogen Fertilizer like 1-0-0 (or any number for Nitrogen) would work.