Felt Tires - Thick Brick or Quick Brick? Chain Rubbing?

I'm shopping around for wheels and tires for my build and I'm quite frankly confused as ****. I really love the fat tire look. I'm going for sort of a cafe racer/board track racer look and I've built it on a traditional Schwinn style frame. The bike right now has 26" x 2.125" rims on it. As far as tires go, the fatter the better. I love the Thick Bricks but they only come in 24". Is this going to look weird on my bike or just make it sit lower? As well, I've heard that these fatter tires can be problematic with rubbing on the chain. Has anybody run into this problem and if so, how did you get around it?
One option I thought I could do is put a Felt 3" wheel on the front and a Felt 2.125 wheel on the back with the Quick Brick or Thick Brick tires. I've learned that when you put the wide balloon tires on a 2.125 rim, they appear to not be so balloon-like...much more indicative of a regular tire width. Still if I could run with the 3" Felt wheels on the front and back, that would be ideal. If you've run into this dilemma, please help! Thanks.

PS. I'm building a custom tank and I see a lot of guys have these nice bungs or gas caps. I've look everywhere and can't find'em. If you have any good sources, please clue me in.

Attaching a current photo. Only about half way there. Those front forks need to be chopped still and a nice Brooks saddle will finish it off nicely.

Thanks for the help VMB. I really don't want to offset the engine and sprocket if at all possible. Do you think using a 2.125 rim in the back could be the ticket?

As well, I saw in one of your threads that if the chains rubs, it's not really a big deal. I would have thought it would rub a hole right in the tire. Maybe not.