For years I always bought my cylinder kits from the dealer. Then New Holland started to change over the glands and pistons and a $40 kit went up to $200 and then to over $300.
Luckily I've become friends with one of the guys there and he told me to go to a business the rebuilds hydraulic cylinders. He turned out ot have just the seals that I needed and they were cheaper than the original kits I used to get. I just put one back together today on my 555E backhoe for $10 in seals.
Kubota L48 Kobelco sk100 Kobelco sko35 case 450 Mack R600
brokentractor.com (877-509-0666) have bought a lot of parts for my case dozer from them real good price and service. Paint Valley Equipment is another good place web site same name or ph 877-774-0081