the valves shouldnt be a problem in regards to how stiff they are as i can have a second manual valve to shut of the system completly therefore the stepper/servo driven valve can be loosend as it dosen't need to be totally gas-tight as there will also be a constant pilot light that besides makeing sure everything ignights properly will also burn of any lost gas.

the only problem with useing servos instead of steppers is that since i realised it was possable for someone like me to build a cnc machine the learning curve has been fairly steep and this follows for ALL my current ways of making a living and i'm starting to get the feeling that maybe i was issued with a pretty small internal H.D

it seems for everything i learn i have to forget something else

so servos may be economical in one way but in brain space they are proberly more than i can afford