Growing 98 plants and need to decide on the size of grow building that will work.

I'm looking for the most cost effective way to build a building of some sort to house 98 plants. It's a legal grow-op so stealth is not important. Hydro seems like the most efficient method space and time wise. I did want to know what would be the best hydro system for this setup.

There is a guy in my town that professionally builds grow rooms, so that is an option.

I live on Vancouver Island to give you an idea of the climate.

I think a NFT system would be best.