I've been creating 32mm rock shox Sid's and rebas with 80mm travel for builds. These tend to have been available up to around 2012, possibly later and until the charger damper came along, havent changed much so parts are still around and service centres will still touch them.
For older frames with v braking requirements, it is more of a challenge as finding forks with rim brake lowers isn't as easy, but knowing that recon, Reba and Sid lowers are pretty much the same and can be interchanged can be useful knowledge.
The pre-2007 (28mm) Sid's are harder to get parts for and to find someone that will service them, not impossible though. I don't know much about lowering these though, suspect they need damper changes.