Fred,
I think all is said here.
My 2 cents are just simple. Keep on building and learning.
For me a drycell with a very small gap is working.
For Hydro a wetcell is the best.
Much of it is related to the water you wanna use.
I preach as long as i can remember, no to use chemicals and destilled, because of many reasons.
1. chemicals eat your hard paid cell
2. chemicals slow down the burnrate of the hydrogen
3. chemicals and destilled water cost money
So, decide what type of water you wanna use and go from there!

br
steve