Hi Jon Todd, the miter station is looking very nice. I always build my drawers with pocket screws and glue. Put your holes on the front and back peices, this makes a clean side with no nails or screws showing. Its fast and dosent occupy alot of clamps. I use 1/4" ply for the bottoms on reg. drawers, and 1/2" on drawer that will see alot of use/weight. The bottoms sit in a 3/8" deep dado, 1/2" up from the edge.
Definatly spring for the full extension, once you use them you want go back to the epoxy slides. I buy in bulk, so if you need some, I might be able to save you some money.