Are there any particular Houdini builds released that support ar2?
Is there a particular version/release of USD that you recommend to be used elsewhere on our pipe to maintain cohesion or are we generally ok to use matching major versions?
We'd like to get some clarification before we start rebuilding the best matching Houdini & Solaris USD builds you see.
Houdini 19.5 uses Ar2.0 with USD 22.05. You should be able to interchange USD files between Houdini (22.05) and other USD-based tools/libraries/DCCs fairly freely. The USD file format is generally very stable and forward and backward compatible. But you'd need to look at the USD github to check for exceptions to this general rule.
You'll need to build your resolver explicitly against the USD library that ships with Houdini (you can't use the resolver binary built against some other USD library), but the HDK in 19.5 comes with a sample that shows how easy it is to do this ($HFS/toolkit/samples/USD).