plasma setup-leadscrew vs. rack & pinion + software

Hi, I'm in the process of building my first cnc plasma unit. I was
hoping someone could answer 2 questions I have .-First the specs on the
table:
I'm basically constructing a plasma table big enough to handle 4'x8'
sheet/plate (5'x10' overall?).
I'll be using g201 gecko drives to microstep 2 ) 542oz/in bipolar nema
34 steppers(thanks dave@ camtronics)
At this point I'm trying to decide ( based on economics) the best way to
move the gantry, so my 1st question is- with this type of
setup,(plasma), what would be a more effective/effecient power
transfer-gear rack & maybe pulleys, or a lead screw,( acme precision
lead screw perhaps?)
I'm trying to get the best torque/speed ratio,(isn't everybody!) -And
based on best option, can anyone give some sizes/pitch,ect
.
(Also I realize that to do a lead screw setup, ball screws would be a
better option , but right now funds are limited,put it into the
electronics& motors)

2nd question- I've seen alot of software options out there,any
suggestions for plasma? I have 500mhz computer, win98se, TurboCad v7, &
corel trace ( packaged with turbocad program for scanning images to
vector files)-Any hints on cost effective ( for now) programs?

I'm sorry to be long winded, I've tried to do all the homework without
bugging anybody, but at this point in the game -this group is a God send
& I really appreciate any help offered-thanks