I have that 5 piece set likes Dag's from Northern and I love it......
I used to have an interchangeable set. Seems like for some reason or another I'd wear em out. Well that's what Sears told me. I got tired of going back to Sears to see if they would warranty them. It was worth the little extra $$$$$ I paid for them to not have to go to the Store for a replacement. Besides that, never used them that much anyway.
I bought this set from Northern, I want to say 3 or 4 years ago, my rememberer has gone on the blink. I know it has been a while back. I got mine when they had their tools on sale, like 40% off or some damn #.
I just got a email from Northern that they have a sale of some kind till the end of January.
http://www.northerntool.com/shop/tools/NTESearch?storeId=6970&N=0&Ntk=All&Ntt=key+ring+pliers&Nty=1&D=key+ring+pliers&Ntx=mode+matchallpartial&Dx=mode+matchallpartialI bought a set that looks exactly like Dag's from Northern, from Harbor Freight. Here's the link and a pic:
http://www.harborfreight.com/5-piece-retaining-ring-pliers-set-610.html
Pure junk. They can not handle the force needed to move the ends on snap rings - every one of them, the tips bend. Untempered or bad steel, whatever - but a complete waste of money - though the money isn't much. So be advised - don't get them from Harbor Freight - they look exactly like Dag's picture, even the same color handles. I have another one with interchangeable tips, don't know where I got it, but it has served me well for years. I needed a really heavy duty one for compressing a really large snap ring inside Progressive's 416 shocks to replace the seals. So I just welded some tempered steel tips onto a large set of pliars, then re-tempered the steel. Here's a pic:

Yep, it's a Harbor Freight pliar. Nice thing about it, it's cheap so I don't mind modifying it - not like quality expensive tools like Snap-On etc.
Anymore, most of the time if I need a special tool, I just make it. Jigs, special purpose hydraulic presses, special-shape hand tools to get into tight places, etc. It's most expedient for me to just make it to fit rather than to try to go buy a dedicated tool which might exist, but probably doesn't.
I'd suggest, if you don't have one already, get yourself a MIG welder and learn how to use it. For this purpose, you will also need the ability to remove metal - angle grinder, Dremel, chop saw, belt and disc sanders, hand held drill and drill presses, and a lathe, all serve in this function for various size and shape cuts and levels of detail. Comes in really handy, to have the ability and equipment to make tools you need. You'll find that expands the possible solutions at your disposal exponentially.