I've done some research on building a 50-39 crank.

I figured that I could use a compact crank and change the small ring from 34 to a 39. This does not seem to be possible because a 39t 110mm BCD ring does not exist?

So, that leaves me with replacing the 130mm 53t BCD outer ring with a 130mm 50t BCD outer ring? I see that FSA makes such a ring, but it would look kind of strange/ugly on a Dura-Ace 7800 crankset (my first choice). An Ultegra 6700 would be my second choice, but the outer chainring on that crank is $$$ and pretty much proprietary at this point.

Any tips would be appreciated.

Thanks in advance,
Bob