The scoop I use for regular size cupcakes is almost exactly 1/4 cup.
Sorry, I can't help with the other sizes.
For weeks I have been looking for the old timey type ice cream scoop with the lever to fill my cupcake liners. I have looked in many commericial supply catalogs, found one and it was $16 plus S&H, and decided I'll stick with my little individual (1/4 cup) measuring cup. Might be a little messy at times, but it works just fine!
Liniti -
Have you tried checking into restaurant supply stores near you? Many of them will sell to the general public. And you will pay a lot less for them in the showroom than you will online.
I go directly to the restaurant supply stores near me, and I have never paid more than $9.00 for any of the scoops I use.
Theresa 
Try AceMart - their scoops are around $7 for the stainless steel ones by Volrath - LOVE 'EM! if you don't have a location near you, try their website - acemart.com
Litini
Here are some on Ebay cheap.
http://cgi.ebay.com/Vintage-Ice-Cream-Scoop-CAPCO-18-8-Stainless-Steel_W0QQitemZ380109705949QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item380109705949&_trksid=p3286.c0.m14&_trkparms=72%3A1729%7C66%3A2%7C65%3A12%7C39%3A1%7C240%3A1318%7C301%3A1%7C293%3A1%7C294%3A50
http://cgi.ebay.com/VINTAGE-PEERLESS-ICE-CREAM-SCOOP-LEVER-ACTION-ESTATE_W0QQitemZ360138519196QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item360138519196&_trksid=p3286.c0.m14&_trkparms=72%3A1729%7C66%3A2%7C65%3A12%7C39%3A1%7C240%3A1318%7C301%3A0%7C293%3A1%7C294%3A50
Liniti -
Have you tried checking into restaurant supply stores near you? Many of them will sell to the general public. And you will pay a lot less for them in the showroom than you will online.
I go directly to the restaurant supply stores near me, and I have never paid more than $9.00 for any of the scoops I use.
Theresa
I live in a rural part of NC and there are no restuarant supply stores around here. In fact, the closest mall is 75 miles away....lol! 
Thanks neighbor....patticakesnc! I've been wanting to jump into the ebay world, I guess there's no time like the present........ 
Liniti -
Are you in Transylvania county, too? My friend, Billie, lives out there. She teaches at a vocational high school out there.
Theresa
I just wanted to post that I just bought a 2 oz scoop (1/4 cup size) and found that it is probably just a little bit too much for my cupcake/muffin pan. I had to basically level the scoop and it was still a smidge overfilled. The cuppies had a very large dome. The rest. supply store had a 1 3/4 oz size scoop as well. I am thinking that one is going to be perfect. I think the 2oz one will be perfect for those paper nut cups/souffle cups. But this is just my experience. I don't like having to level. I would rather have the smaller size and just smear it against the side of the bowl to level it, which I think would then make it close to 2 oz. I am sure I will still get use out of it. It certainly makes scooping cupcake batter a little less messy.
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