Stainless steel brake line / fitting question

[767Jockey]

I'm trying to get the rear brake lines in the Contemporary flared, bent and fitted. I bought a Classic Tube stainless 3/16" line fit with fittings. One thing I didn't think of at purchase was that the rear calipers use bubble flares. I have the bubble flaring tool, this is no problem. The problem is that the only 3/16" bubble flare fittings I have are not stainless. Will these work anyway to make a good seal, or is there some reason other than appearance that I need to use a stainless bubble flare fitting with a stainless line? Of course it's Sunday and all the import parts stores are closed. I would like to get started on this but I need to know if I can proceed or if the rest of the day is wasted without stainless bubble flare fittings. That's assuming that I can even find them locally tomorrow, who knows how common these things are in stainless..... Any info is appreciated, thanks.