I have a PCC, in the beginning it was in fact the only thing I had to load my 510. They are great, but these days I'd rather recommend an eGo. In this weather, no leaking problem, either, which for me is an even bigger plus than battery life.
If on the other hand you want to stick with normal 510s, I'd recommend getting a PCC.
I cannot, at the moment, recommend even looking at mods for 510s. Seems that Joye 510s run on 3.1
instead of 3.7 volts, as everybody thought, which means they get quite hot and sharp on anything 3.7 volts. Some people don't like that. You should at least know what you are doing before ordering one.