First, as I understand it, Biodiesel works best in conjunction WITH diesel fuel, sort of like an additive, or diesel stretcher.
I personally used to buy from local stations, but because of the high price, I researched and found that I could get off-road (higher sulphur content) diesel or "red dyed diesel" for much less. I bought two 55 gal. drums and had them filled at a local fuel oil distributor. The difference was $1.25/gal as opposed to $1.75/gal. If you would not use up that much fuel over a fairly short period, you would need to treat it with a biocide to keep bacteria from turning it to muck. Not a big problem. You can ask the dealer what the cetane rating is for the diesel, sort of equivalent of the octane rating. I think brand doesn't make a lot of difference. John