OK, I did some research here and discovered I was wrong, sorry. The 27 MHz version is Abracon ASVV (I have two seperate transverters, one for an Octagon (27 MHz ref, Abracon) and one for 'other' (de facto standard now) LNB's with 25 MHz ref, Taitien).
The 25 MHz VC-CXO I use in my 'current' setup is this one. Iirc it has the same (phase noise) characteristics as the ASVV series and is cheap (around 2 euro).