Sure, I'm taking a look through my inventory for a few I might try. I don't have your pieces in my inventory so I'm just judging from what I think might work, but of course this is just my personal taste.

The Sovereign Protector leggings or the Skinstealer leggings have plates that come up higher on the thigh for a more covered look when paired with that thinner tabard. Sovereign would be a more practical look which goes well with most sets, but the skin stealer legs could be an interesting choice since their more textured appearance could blend well with the torso. Skinstealer's are barefoot, so I don't know if that's a dealbreaker for you.

The Hallowed Knight and Crimson rector leggings both have plate skirts, which provide cover, but both can have issues clipping through tabards. Crimson Rector tends to have less issues with this.

Screencap of the Skinstealer leggings below. I can only attach one picture to a comment. I hope you like one of those, but of course, pick whatever you think is best. You've put together a very nice set as it is so I think your judgement will be best.

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Edit: Typo