We're working a similar transition from AIX to Linux (RH). We have had a bit of a challenge with Java (we were not using the PTC-provided java but instead AIX 64-bit Java) and more so with Apache. I had to hand off the project to a co-worker so I don't know the details but know where to ask.
I did ask PTC first about AIX to Linux and they reported no issue. I'm afraid this doesn't guarantee Solaris to RH but I think it's likely OK.