does rim size really matter in order to get featured?  

yes.

but it depends on the look of the truck. if you buy a brand new truck and customize it in a contemporary way then an old school set of 17's won't look right.

but if you have an older truck and go for a traditional look with it than you can get away with smaller wheels.

then again, a big truck looks wrong with tiny wheels. The wheelwells of todays trucks are huge thus making wheels that used to be considered too big, look perfect.  

yeah, regarding big wheel wells, that's a good point  

im thinking of downsizing the wheels on my '67.

the 25 series tires make me think i'm going to ruin the rims pretty quickly.  

start posting your truck/year/drop height with your size of wheels your rolling. I'm interested. Personally I want to run no bigger then 20's on my 88 c1500 thats dropped with a 5"/7" ...if only i had the money