I will probably go for a fancy bushynose pleco. They seem less expensive and get just the right size.
What does your timeline look like for the upgrade? If you are getting ropes like the ones I got then you'll proably be fine for awhile. Mine were all 6-8" they don't grow super fast either. If they are bigger then 12" I'd say you might want to wait till you get a 4' tank 75gish. A standard 50 just doesn't have a good dimension for a long period of holding for the ropes. So to sum it up I'd say super small ropes(below 10") good for about a year, 10+" you might want to wait till you get the bigger tank. I thought you were getting a 65? While it'd be better to have them in a 4' or 6' tank ultimately, a 65 has a good bit more swimming space then the 50.Starting off in a 50 gallon, could you do 3-5 ropes, or is that too much? It seems like it would be overcrowded. I am open to cleaning twice a week if needed. The tank will be heavily planted, with wood and caves for hiding to make them feel more secure. I will ensure there are no places to get stuck either. I don't want any ropefish to drown!
Yes multis are great. Again 5 would be better. They are social but at the same time squabble a bit amongst themselves. I've had them in a few different tanks. If I've gotten 3 2 usually beat up 1. If 5+ no issues. I'm guessing paired off...? Never seen any fry though. A lfs does breed them. But I've read they have a parasitic stage in their development based off a particular cichlid. I've also read that they can grow 7-10" biggest I've seen is 5". I'll have to ask lfs about raising their fry.For synodontis, now that I've looked them up, I think I would pick multipunctatus, maybe 3 of them. I would get more but dang! They are expensive.