Ok, so I used to be really into working on bikes, but have gotten out of practice and have forgotten some stuff.
I'm working on an early 90's C-Dale touring bike. It has a 7 speed cassette in the back, and is hooked up to bar-end shifters. It needs a rear derailleur.

Do I actually need a 7 speed RD, or can I simply use any derailleur that I want so long as I am willing to give up index shifting and simply friction shift with the barcons?
Of course, I'll have to set the stop screws on either side so that it doesn't shift the chain off the gears.

I'm just looking around fleabay and it seems like 8 speed RDs are a lot easier to find. I want to get a decent one like Deore or better.

If the shifters are Shimano, any 7,8,9 speed Shimano indexed MTB derailleur will work.

+1 no worries. No need to friction shift unless you want to.

Almost any Shimano RD you pick up will index with it, but may not have enough big cog clearance or range.

which site are you referring to?

Hah. There's gotta be some sort of corrolary to rule 34 in online marketing...

Ha!!! I was actually referring to eBay, but of course, enogh people call it "fleabay" that now, there actually IS a website by that name!! I love it.

Yes, the barcons are actually ultegra shifters. I put the bike together pretty nicely a few years back, but needed to steal it's RD about a year and a half ago and I'm just getting around to replacing it.

Thanks for all the tips guys.

As for this:
I have to admit... I do kinda like it. There is something so... simple and clean about it. It's all up to my feel and my sense of which mechanical piece is doing what.

FYI: one of those 2 fleabay links I asked about may be an attack site and I may have picked up a malware type virus from it. just had to get our IT dude to clean my computer.

Than maybe you should go back and remove the link before someone else clicks it?

oh good idea!