Wheels and Tires need some help please

[desertdogg]

Im currently in the market for some wheels and tires but Im a little confused as far as what offsets work on this truck where they are tucked in enough where it wont rub on the fenders I have not done a suspension drop yet but will soon. Here is what I want to get 20" wheels all the way around with 10" wide in the back and 8.5" in the front. The wheels I like are JD wheels riddler series 645 it says these rims have a zero offset, so would these work after a 3.5" drop in the front and a 5" drop in the back ? also what tires would work to fill the gaps I want it to sit level and the wheels to fill the wheel well...I would apreciate any help here I have searched and not finding a whole lot, I know many have done this type of drop and have some sick looking trucks My truck is a 1972 c10 LWB....please help...thanks