If looking for alternatives, you can not beat a Rolleiflex. Only limitation for many used to interchangeable lens cameras is the fixed lens but, as history has shown, it is a limitation in only in the hands of persons not willing to let their feet do the walking.
These are virtually bulletproof, reliable beyond belief. Iwas recently asked whether a Rolleiflex or Leica was more reliable and after thinking for some time, had to agree the Rolleiflex was probably the more reliable. As for repairs, there are a number of very good reliable Rolleiflex techs and seems to be a lot of repair parts available. I suspect with the final(?) death of Rolleiflex production, even more will be available and as it is mecahnical, I can see aftermarket parts manufacturing even popping up. My Bronica will probably hit the for sale shelf before my Rolleiflex.
The Yashicamat 124G is a virtual knockoff of the Rolleiflex at a lesser price and has an very good lens. Shutter and winding not as refined and seem to be not as reliable and it seems parts are more difficult to find. However, reliability is very good and unless really banged about most are still working. They are newer than most Rolleiflex models and the shutters are fairly easy to work on being leaf shutters.
If you need interchangeable lenses, and not willing to accept the auxilary lenses for wide angle and telephoto for the Rolleiflex and Yashinca, then look for a Maymia C series tlr. They were issued in 2 series and several models in each series. Both take the same lenses with some exceptions. These are a bit heavy to carry around but a number of owners do it.
As for the type of mf design, rangefinder vs slr vs tlr, it is personal choice and none are lesser or bad. I've used all 3 formats and all work well once you get used to the feel and controls. Though my main system is an slr and I've never regretted owning it for about 20 years, my choice por a favorite is the Rolleiflex which I've accumualted items for over the years and to me is Rollei. Not a versitile in some types of shooting such as close focus and macro, wild life and similar. But for general shooting that most due, I used the Rolleiflex more.