Hi there. New sulcata owner here. I am adopting 2 adult sulcatas next weekend - one 70lbs and one 40lbs. I am debating on building a custom house or modifying a premade shed from like Home Depot or Lowe's. I live in Sacramento, CA. Any recommendations on which would be better? Also, is an overhead heat source better than a pig mat? The lady I am adopting them from uses only pig mats and said it provides adequate heat. Thanks for any advice.