OK, you want to look for a wheel in the +20 to +25mm range. What style are you looking for? Simple 5 spoke, or do you like some flare in the wheels. Black, chrome, polished?
Depending on the width. a 10" wide wheel with an offset of +20 will fit differently then a 8.5" wide wheel wth a offset of +20.
night hawk - Wheel offset is how far the mounting surface (that mounts to the hub) is offset from the center of the wheel. Negative offset means the mounting surface is closer to the innner wheel lip (pushes the wheel out of the fender more, the lower the offset). Possitive offset means that the mounting surface is offset from the center of the wheel towards the outer rim lip (sucking the wheel into the fender).
A 10" wide wheel with no (or -0- zero) offset would mean that the mounting surface is centered between the inner and outer wheel lips. Essentially if you measure from the wheel lip in to the mounting surface there will be 5" of distance.
Same wheel, but with a - 25mm offset means that the mounting surface is "offset" 25mm from the center towards the innner wheel lip.
Hope that makes some sense.