Thanks for the comments so far, I must admit I feel a little under pressure seeing a couple of the names "signing in".
I think I'm swinging towards DX on the Orbit NeilM, I've got most of that groupset kicking about. Some of it is on my Proflex 552 so I'll swap it for the LX which is the original spec for the Proflex anyway (sort of win-win
The Zinn will probably be the bike that comes together the quickest because apart from a polish and some gentle touching up, it's good to go. It won't be to everyone's taste but I believe that XT is an improvement on the original kit that this would have come with.
love the orbit. had my eyes peeled for one for years, but no luck.
I'd been typing "orbit" into ebay on an almost daily basis for a good while before this one showed up (my size too). Then it was just a matter of outbidding this lot once it had found its way into the market-watch section