A lot of the better dealerships have it too. I know triple-s in ogden, Tri-city in centerville, and Vescos in Brigham sell it just take your cans in. I'm sure most the other dealers have it.
Jardine Petrolium in North Salt Lake, Directly off I-15 has Bulk VP 110 leaded race gas, I bought my last batch at 8 bucks a gallon, but before the price spike it was 5 a gallon, i am sure its cheaper now, you just take your own container and it makes it a little cheaper.
Call cardwell Dist. and ask them where to get Sunoco 110, they will tell you, i just forgot the name of that plac.e