For 6s usage, 35v low-ESR caps (you can tell by the 105*C rating). Actual capacitance varies. If I'm gonna add caps, I like to at least double what is currently on there. IIRC, the MMPro has 3x220uF caps (660uF total), so anything around that would work. You could get one cap or 2-3 smaller ones - doesn't matter (although I personally prefer mutiple smaller ones for better heat dissipation and transient response).
The TVS should be similar/same to what Castle puts on the MMM. Can't remember off the top of my head the exact part number though.
Or, you could get something like this:
http://www.shopatron.com/products/pr...ber=5685/135.0