I have had Cleaveland seats in my RV6 (Sheepskin and cloth) which fit great and were very comfortable. Experience showed that over several years, the sheepskin got stained/discolored from sweat. Other than that they have over 800 hours on them and held up well.
I have also used the foam seat cushions from VANs and took them to a local auto/boat upholsterer and had them covered with vinyl. They also looked good and fit great, in the RV6.
I purchased an in progress RV8 which included a new cloth Orndorf interior. It looked really good but I don't have any experience in flight with them, since the plane isn't done yet. Workmanship looked great and they fit nicely in the plane.
I sold the Orndorf interior because I wanted leather and purchased from Aero Classic. The seats were pricey but are beautiful and fit nicely in the plane. My wife even like them...and she's PICKY!!! Again, no in flight experience, yet.
Overall, I would say that the interiors from any of the above are worth their price and you'd be safe going with any one of them. The big concern would be the type of material you want. My opinions on that are as follows: Cloth - very comfortable but could stain and may wear quicker since you will be stepping on them, Sheepskin - very comfortable but the sheepskin stains and they do get matted, so regular cleaning is in order, Vinyl - a good compromise between cloth and leather...wears well, easy to clean and in m ost cases people can't tell the difference between vinyl and leather, leather, to me is the way to go...wears like iron and is easy to clean.
To me, the weight difference between all of the above is negligible, at least as far as the seats go. If you start doing a lot of side panels, etc. I think cloth is the lightest.