I have a machine roughly the same size. I tried the 116 oz-in bipolar stepper motors that are sold on the Xylotex website. They are underpowered in my opinion for your size machine.
I bought some larger NEMA 23 280oz-in bipolar 200 steps motors and have been very pleased.
http://www.seanet.com/~dmauch/ Just tell Dan you want it to have great performance with a Xylotex board and he will recommend the proper motor. Any thing larger and you will need bigger drivers (Geckos)
I use the Xylotex stepper driver control board. It was very confusing to me, but after awhile it all becomes clear. I bought a prebuilt controller, because I am not good at electronic either. A kit seemed way out of my skill level.
http://www.xylotex.com/
I bought a 24V 6.5 amp DC power supply from
http://www.mpja.com/listitems.asp?dept=3&main=1
Motor cables can be purchased from Xylotex, or from a guy on this forum, Jfirey. You could just send him a private message.
Good luck.