i was just gonna suggest that
http://www.cardomain.com/item/STIS04ADAPT
for the ground? well. how many watts is your amp, if its likeunder 1000, i wouldnt really worry about 0 guage.. you can if you want, or if you have any left over posative 0 guage, even though its the same color, just use that. wire is wire. a plastic sleeving isnt gonna change that, JUST MAKE SURE YOU LABEL WHAT IS GROUND AND WHAT IS POSATIVE IF YOU USE THE SAME COLOR! dont want you blowing your amp =P
just use what you have. simple as that.
get those 2 0->4 guage stinger terminals, they should be perfect for what you need, unless you have the weird terminals with the plate instead of the hex screw (rockford fosgate and knukonceptz have the terminals that you can use with the stinger wire adapters) the ones that have the flat square washer and the screw that holds it down (where you have to split the wire in a Y or use a Y terminal) you should get one of these
http://www.cardomain.com/item/LITBSRT10 and take the flat washer out, and screw the screw thru that hole.
thats all depending on what kind of amp terminals are on there. have any pics?
if you end up buying anything from knukonceptz, just buy 5 or so feet of 1\0 for $10 you cant go wrong with that price. that way you can just have all 1\0 guage, and not have to worry about anything stupid like 2 4guage wires
