If you are going with Magom cylinders this french forum has a guy who modified his Magom cylinders to be more reliable as far as leaks.
http://camions-rc.fr/forum/viewtopic...4474&start=240
He might also have more information on what he did in this build thread, I'm not really sure where.
http://camions-rc.fr/forum/viewtopic...2937&start=360
I use Google translate to read his stuff.