Jproj,
In my experience, I have seen APV, PV Elite and Compress, in the above three software, the best software is Compress to fulfill your requirements.
Compress software is available in two versions that are Dos & Window version, and there is a lot of future available in the window version...
I am fully agree with Butelija comment and that is the normal practice to use standard ANSI B 16.5, C.S flanges with Titanium stub ends.
Cheers
Babu
PV Engineer
Singapore