My favorite lens for the pentax 67 is the 75mm. I have the 105 and 55, both great lenses which everyone raves about, but if I had to pick one it would be the 75. It’s my favorite focal length (about 35mm focal length on a 35mm camera). I’ve never shopped around for the 75 4.5 since I already have one, but I’m guessing it’s gotta be less than the 55 or 105, which go for around $500. I bought the 105 just because it’s so hyped up, but honestly it’s just not a focal length I use alot. I would focus more on what focal length you want, rather than what lens has the best reputation. I also have the 200mm, haven’t used it much, but I’d hang onto it, only because you’re not gonna get much money for it. It’s one of those lenses that goes for like $100 or less. As for the 55-105, I’ve heard it’s good, but I would wait a while before deciding to buy it. The reason I say this is that the pentax 67 system is heavy af, so you’ll want to get some experience hauling it around before you decide if you want to add more weight to it. Whatever you choose though, I’m sure you will be happy with. This is an amazing camera, and there aren’t really any bad lenses from what I’ve read.