If you can compose and focus on a 35mm screen at waist level then you must have eyes like a hawk! For street photography (which presumably implies discreet photography) use a 120 TLR Rollei or Mamiyaflex and get a decent sized screen and a quiet shutter.
I collect Miranda's, the lens are very good, and E or EII has shutter speed priority and interchangable viewfinders, which I think is ideal for shooting from the hip. The meter is in the camera body, unlike the Nikon F, so you can still meter and use the shutter priority auto and the shutter speed read out when you change finders. A 50mm 1.4 or 1.8 or the 35 2.8 would work well in stealth mode. But no motor drive or winder. The viewfinds are somewhat dim compared with modern 35mms. The meters on the E have not held up over the years so make sure you get a camera with a working meter.
Equally, these medium format TLR's you'll only get 12 exposures before its time to reload. And you'll only use 75-80mm lenses, which are 50mm in 35mm terms. I prefer something wider.
If your using from the waist, you'll not be eyes right up to the viewfinder, so it being large enough for two eyes is a non issue. If your close you'll use the magnefier and its a non issue.
My old Miranda Sensorex has a removable pentaprism. In MF, I think I'd go with the Hassie for hand-held, maybe a rolleicord Vb or Yashica Mat (EM or 124)