Ether = Diethyl ether, its used as an industrial solvent these days but due to its use in the past as an anesthetic , and its volatility its a controled substance here.
Most find a freindly chemist to purchase it from, but since you are in the USA , Pre mixed fuel would be an easier option . I beleive there are about 4 suppliers that will post fuel in the USA.
As ether is also used by illicite drug makers, you will get 1001 questions as to why you want the ether.
Ordinary auto diesel can be used in the fuel mix, as above, but ether is needed as well. This is because our model diesels opperate at a lower compression ratio.
Stewart