What style of street photography do you have in mind?
Shallow dof type people shots? -FE55
Long lens sniper? -Don't have for now. Longest is 24-70
Wide view contextual street shots? -FE35, 24-70
to me, the A7/r rewards the MF lens user more than the AF user for now.
If you are willing to use some MF lenses to fill up the gaps, it should work out fine.
Otherwise as I mentioned before, you are better off with your 6D and a few primes to keep size down.