Has anyone built their own homestead type walk-in freezer/cooler unit. How did it turn out? materials etc?

I have aquired a new freezer unit. In its own weatherproof box somewhat similar to a window air conditioner. This was meant to keep about 200 cu/ft at -5º. I thought I might build a small walk-in or a freezer with large doors and baskets. Can you add a cooler as part of the freezer by thermostatically(sp?) robbing cold/cool air from the freezer?

Current freezers always has what I need on the bottom. Plus I'm thinking it could replace 2 older 15 cu/ft freezers more effeciently?

Thoughts, suggestions, recommendations and experiences are all appreciated.