You cannot use stainless steel reels in Paterson tanks.
The plastic reels that come with the Samigon tank that B & H sells are probably the same as the AP reels (and tanks) that I have. They are compatible with the Paterson tanks, and I find them easier to load 120 on than the Paterson reels, due to the fact that they have much wider feed flanges.
If, however, your difficulties arise from humidity or something else that afflicts all plastic reels, that may not make enough of a difference.
That being said, the better stainless steel reels ($55.95, and apparently actually Hewes reels) at B & H are more likely to be straight and smooth, so they are less trouble to load.
I can make them work, but not by using the clip (applies to all 120 reels).
Matt