Welcome to the mad house Paul.. It will be nice to see some of your work on here. 
In my opinion for what it's worth is have a go at the sierras. Or aero's as some call them, single tube pens, simple to make and simple to build.
They are good for a "strip back down" as well if you have any problems..
Don't get me wrong, any can be stripped back but these are easier.. 