need some advice, (wheels and lowering)

[no1uno55]

I need some help, i want to lower my truck and put wheels on it. i thinking
5-7 on the lowering, and i wont the boss 338s (black) in a 20x8 all the way around.

thats where i need help.
lowering=

front-- spindles and springs or spindles and lower control arms. or ....
back-- flip kit and maybe a block or .....

then the wheels what back spacing should i get them in

i drive this truck daily but will be parking it to repaint (the blue a little darker and where the white is will be black) and do the above this winter. also a cowl hood and a phatoom grill.

also where is the best place (price) to get the about parts

thanks in advance.