I'm not a good enough judge so I'd appreciate your guys' input. I have a polish doe (black doe pictured below) and I want to improve my herd by fixing her structural issues of peaking too far forward and being long in the middle-section causing her low shoulders. Please give me some advice lol because I really want to raise the best buck for her but can't decide.
It's a little tricky judging rabbits from single photos, taken from different angles and in different poses, so please take the following comments with that in mind.
None of them seem to be posed correctly except your doe (who has her head up but otherwise seems set up right) and maybe #2, but I can't see his feet so I'm not sure. None of the little bucks appear to have tremendous depth, but having said that, to my eye, the two that jump out from this lineup are #2 and #4... #1 and #3 look long in body, even when they're overposed.
Number 2 looks fairly short and round, possibly slightly undercut in his hindquarters, but that may be a posing issue - can't really tell on him, but the others all appear to be overposed (hind feet tucked up past their knees and near their shoulders). Also, I can't tell due to the angle of the photo, but it looks like he might have okay depth, though not as good as your doe's. His eye doesn't appear especially bold, but again that could be the angle of the photo. His ears tend to fall apart rather than standing up nicely together, and the tips turn in at the top which can be a sign of a lack of substance, but IMO neither of those things are deal-breakers.
Number 4 has the flashiest and most correct head, eyes and ears. He has good width between the eyes, a short muzzle, well-set ears that are short and seem to touch all the way up, with good substance and furring. He doesn't look as short and round as #2, but I'm thinking that may be due to his pose: his hind feet are pushed well forward of his midline, directly under his shoulders, and that can cause the appearance of being both flat and undercut. Proper posing would allow a much better assessment. It also appears that he might be pinched in the hindquarters, which may or may not be due to overposing. I'd want to turn him over and see how his hind feet sit - are they wide and parallel, or do they make a "V" with his hocks close together and toes pointing out? I really like his head, eyes and ears, but
if he's actually pinched, I'd pass on him; I've found that pinched hips are hard to get rid of, and they can make kindling difficult for does who inherit them.
Number 1 has a good bold eye, but IMO that's all he really has going for him, at least judging from this photo. His head looks more doe-like, he's long and fairly flat, and his ears are on the longer side (long bodies and long ears often go together). His color isn't particularly bright or deep, and he seems out of coat and maybe a bit rough in flesh condition. Some of that could change as he matures; all four bunnies look pretty young.
Number 3, at least in this photo, may have a correct peak, but a long shoulder. His eye isn't as bold and his muzzle may be a bit snipey. The most concerning to me are his ears, which look long, fall wide open and may be lacking in substance. Again, long bodies and long ears often go together.
Polish have 25 points on body type, and 45 points on head, ears and eyes, so you want to keep that in mind when choosing a buck to complement your doe. She seems to have good depth, but I agree that she is a relatively long-bodied doe with a long/low shoulder, and an early peak and long flat midsection that slopes off toward the hindquarters. She does however look like she's full at the table, not pinched or undercut, which is quite important especially for a doe. She may be a bit hollow in the loin and possibly a little narrow in the hindquarters, but #2 or #4 might help with that. She also seems to have longer ears and a less-bold eye; taking all this together, I'm wondering if she could possibly be a false dwarf? That's not good for showing but false dwarf does can make great brood does. What's her weight?
Taken all together, I'd want to either get more photos of #2 and #4 in proper poses and various angles, or better yet, get my hands on them before making a decision. I like #4's front end but I'd really want a look at those hind feet before choosing him, and I'd want to confirm my impression of #2's head, eyes and ears as well.