18 or 20 wheels with larger tires - not staggered

[Ziegelsteinfaust]

What is your ideal tire diameter? How much is your truck lowered depends on how you approach tire selection. I prefer to lower then decide on tires, and trim a little if it can be fit better.

From there you can play on tire rack to find what tires have that rough outer diameter.

Also towing with car 20's can overload them, and increase of tire failure.

18's at the same tire height as low profile 20's have a good deal more capacity.

So I in general at this point go with 18's of your two choices.

A size to consider is 17's, and on a stock height truck 275/60/17's fit well, and look like 15's. In terms of wheel to tire ratio. They have good weight capacity, and meet the other then looks qualities you sound like you want. 255/50/17 look good on a lowered truck, and work all most as well.