Should be still available at a hobby site for airplanes,and the RC car racing tracks, but you can buy lab grade ethanol, castor oil also because it doesn't burn and nitromethane. I can get nitro at the local racing fuel place and maybe Summit. I have seen fuel at Wallyworld in the toy area, but only pint cans. It doesn't store well opened because the nitro is really volitile and evaporates, while the alky just wants to absorb atmospheric vapor.
For pints and quarts, just go online. Dont buy a gallon it will go bad before you use it up
FAI fuel is just alky and 20% by volume castor oil but my COX engines really don't like that.
Dont go above 10% nitro by volume. Tends to melt piston tops otherwise