HHO Wet Cell Voltage and stacks question

I'm making a 12v wet cell as a side project (Still a noob to HHO!), and I'm wondering this:

Is it better to have a setup of
-nnnn+ +nnnn- (is there a difference if it was -nnnn+nnnn- instead?)
or
+nnnnnnnnnn- ?

I guess what is the best plate arrangement for 12 plates or is it worth it to have 14 plates?
Is there a reason to separate the plates into two stacks or keep them as one stack?

I'm using --nnnn++nnnn-- with 28% Kno and it works good