Interfaces & linear scale for LinuxCNC

Hi,
I originally wanted to run a cheap DIY cnc machine using an old Intel Atom dualcore computer which has an LPT connector. But meanwhile I start thinking about higher quality components.

Same specs:
-stepper motors (already exist)
-linear rails for a work area of 1000/600/200mm (already exist)
-spindle Kress FME800 (already exists)
-stepper driver board with 5x Toshiba TB6560 (already exists)
-USB connected hand controller/job wheel LHB04 (already exists)

Now I wonder if I'd better go for an network/USB controlled Mesa card to get rid of that old Intel Atom computer and be able to use any machine (probably a modern notebook).

Also I would like to bux linear scales for my build, but couldn't figure out how they would be connected to LinuxCNC.
Is there a lis with reliable (but not too expensive) supportet linear scales?

And would you rather ust the Toshiba stepper driver board listet above or get some modern alternative?

Since I didn't really start building it, I'm free to change components for the good

I'm going to weld the frame for my machine. So I wonder what's the best way to start? At the moment I think I'm going to build z-axis first and depending on it's dimensions I can design the x-axis, then Y-axis.
But for designing the z-axis I need to know which linear scale system I need to mount and what size it is.

Since this CNC machine is intended to build electrical guitars, I don't require the highest precision, but I'd like to have as small tollerances as possilbe for a reliable pricetag.