Well Calesta, unless you've already purchased some stuff online or something, maybe I could save your some trouble... Lowes carries everything you need, except for the box and mounting brackets(although you could probably make something with what they have there...).
I used 4 ga for the starter and 6 ga for the fusebox. After doing it I realized that 8 ga wouldof been maybe better for the fusebox, because I had to trim some wires to fit 1. into the ring connecter, and 2 into the fusebox itself.
The 4 ga wire is $0.25/ft.
The 6 ga wire is $0.19/ft - or something like that.
Bought some connectors for connnecting the 4 ga to the starter and ring terminals(if you don't already have some layin around somewhere), and it was about $5.00 with some heat-shrink tubing and stuff.
So all in all I'm sofar about $20 into it, but I still have yet to buy the box.
Like TurboMirage said, Advanced Auto's Marine battery box's work pretty well, and I know they carry mounting brackets, so I'll probably just buy one of those.
I've seen pretty good kits on Ebay for around $70-80, but then again... you can have that for 1/2 the price by doing it yourself(which I know you can!)
Anyway.. Just tryin to help a 'brotha out.