So I got my fathers 70's Motobecane Grand Tourning. I was just riding around the neightborhood and the rear derailleur broke. I think I "overshifted" the friction shifters, if thats possible.

I was looking for a suitable replacement, does anyone know what type of suntour was on that bike?

Also I would like to know about rear derailleur compatability. Are they made for indexed or friction only, is the number of speeds important. I would like to get some indexed shifters too if anyone knows a cheap alterantive, Im not looking for new or flashy just something that works. I really like the bike if I could get it working.