1. best way to cut the bottoms out of the drawers being thin sheet metal?
With a Side Cutter i think you can handle this
2. what lighting to use given the previous dimensions
i think you can put in a 200W CFL, search on google for cheap price, ive got one from Plug&Grow, envirolite is also recommendable
3. ventilation aspects? 2 pc fans 1 passive air intake? etc?
2x120mm Intake and 1x120mm Outtake (Intake needs double the size of outtake)
Wire all the fans with a old Pc Power Supply, when you need i can search for you how you start a power supply without a computer
When you got temp problems you can put a plexi glass under the CFL light, i also do this in the next few days, people say it solves often theyre temp probs.