No problem, happy to help - realize that I'm no expert however.
Japanese Deepwaters are a whole group of zoas that hit the industry big last year. Interestingly enough they are not out of Japanese waters, nor are they truly deepwaters. It was simply a name that was attached to this particularly brightly colored group and once the name stuck it became a great marketing gimic and resulted in lots of hype, so they initially sold for quite a bit more. Lately the hype has dropped off, and the price has dropped as well. Many polyps that were not truly imported from the same place/depth were given the monicure and sold as deepwaters simply so individuals could charge more for them. The left hand picture of the last set is an example of one that I have seen sold as a Deepwater which isn't.
Perfectly understandable - smaller polyps are going to fit better in your smaller aquarium and prevent it from looking overcrowded.
I Don't have any personal experience with that particular one, but based on the fact that there are multiple polyps in the picture rather then only one, I would be inclined to guess that is was on the smaller size, and the skirt appears to be shorter. However, in all honesty, the polyp size may be misleading, based on how the photographer cropped his/her picture.
IME, the Deepwaters are typically small to mid-sized polyps, none of which have a long skirt. However, you should be aware that placing zoas into higher flow areas will typically cause the length of their skirts to increase.
The ones in the 1st picture that I have do not have a particularly long skirt, and they are a smaller polyp - in fact it takes a macro lens to get a real good view of the colors like you see in the photo - but again, a very nice, small zoa. The 3rd picture looks more like another pink panther morph to me, and I would hesitate on it because you may find in somewhat similar to the one you already have. However, there may be enough variation in the color that you don't mind. I have hot pink Pink Panthers which are almost a purple color, and then I have Pink Panthers which are more of a faded red color. So as Spanko said, it really comes back to what you personally prefer.
A couple common misconceptions that are propagated in the hobby. Some will tell you that if its a paly, the polyps will eat - if its a zoa they won't. Again, not true. The difference between zoanthids and palythoa is actually in the way that they construct their polyp - in short, palythoa use sand grains and zoanthids do not - so if you can examine the stalk of the polyp and it feels grainy its a palythoa, if not its probably a palythoa or a protopaly. In truth, there is no simple way to distinguish a palythoa from a zoanthid - zoanthids generally grow in mats, palythoa are generally single polyps, but even that doesn't always hold true. Nor are names a true means of distinguishing them. The People Eaters are commonly referred to in the industry as palys, yet in truth they are "Zoanthus giganticus" or giant zoanthids if you will, and not a palythoa at all. With the exception of Palythoa grandis, the common button polyps (in brown, green and cinnamon colors), Nuclear Green, Purple Death and a few other morphs of this type of palythoa, there are few true palythoa in the trade. Most protopalys are invasive, so they are not typically traded, instead people often ask how the heck they can kill them off and get rid of them.
Sorry, that probably isn't real helpful for you. of the ones you pictured, If I were guessing which were smaller polyps with shorter skirts, I would probably guess 2, 4, and 5 in the first set, 1, 4, and 5 in the second set, and most likely all three in the third set. I would definitely stay away from #3 in the first set, and probably #1 (although it might be more of a medium polyp), and #2 and #3 in the second set (both are PEs).
Some named varieties that are not too expensive and would most likely fall within your desired size/skirt are going to be Cherry Bombs, Pink Panthers, Mint Chocholate Chip, Deepwaters (several varieties are now named - Fruit Loops, Lakers, etc), Kryptonite Explosion, and I'm sure there are lots of others as well. Stay away from anything referred to as a paly, because that is going to be a larger polyp, regardless of whether it is truly a palythoa or not; Armor of God, Devil's Armor, Nuclear Green, Purple Death, Button polyps, any Grandis morph, etc. Mid-sized polyps like Radioactive Dragon Eyes, Eagle Eyes, Whammin Watermelon, etc. may or may not work for you.
Also keep in mind that lighting will have an effect on polyp size. Less light typically results in longer stalks and larger discs, while brighter light will typically result in shorter stalks and smaller discs.
HTH
