4.3BSD or Ultrix?

[T]

My organization's backbone networks is Decnet which I can't talk.
since I have two VAX (11/780, and 11/750) and a Sun (3/160) running under 
UNIX 4.2BSD. Since is a must that my VAX 11/780 becomes a network node
I'm facing two alternatives :

1) I convert my 780 into a Ultrix machine.  

2) I prove that Ultrix is not quite 4.2BSD and that the conversion
   will be more expensive than to buy a uVax to be used as gateway.

My intuition tells me to stick to UNIX and get a uVax, but I need
more arguments than that, to convince my administration. Any info
concerning this issue will be very much appreciated.

Carlos Perez
Department of Electrical Engineering
Concordia University
Montreal, Canada
UUCP: {decvax}!utcsri!musocs!deervax!carlos
CDNnet: carlos at deervax.ee.encs.concordia.cdn