Time to swap out my wheels and tires but...

Please help a newbie out.
So I bought my SR5 Double Cab 4x2 last week and I'm ready to put wheels, tires & shocks on it.
I just upgraded from a 2004 4x2 double cab pre runner and had 16" method double standards on BFG all terrain KO2's and bilstein 5100's all the way around and loved the look on it.

I'm going for something similar on my new Taco. I already have my Bilstein 5100's for the new taco here at my house but have not had them installed yet. Probably going to set them at the 3rd notch when I do.

With all this said I need help with tires and wheels. I am clueless about tire sizes and wheel spacers and wheel size. I'm almost 100% sure I will go with BFG KO'2 again but am open to suggestions.
What tire size would you recommend?
What about wheel spacers?
Should I go up to 17" wheels like this guy at a shop told me? and if I do that then do I have to "re calibrate" the odometer?

What is the difference from 265/75R16 and 270/75R16, etc etc. I'm not doing a 3" lift or anything like that for now, maybe in the future i'll do an ICON stage 2 lift or something but I can't drop 2K on suspension alone just now.

Any advice would be helpful because I want to upgrade wheels and tires this week.
THANKS!