Thanks for the responses, really appreciate it.
Unfortunately it looks like the photo trader mag is no longer in print. However I'll keep an eye out for those models mentioned and do some more research on dimensions, might d/l the manuals to get a better understanding of them. I intend to store it on a trolly so I can wheel it in and out of the bathroom.
With regards to a good lens, they should be easier to source as they are easier to post and I'll be happy to take the hit on postage if they're in the US or UK once I know what to look for. If I understand it correctly the standard mount is the M39 screw mount of Leicas but every so often there's an enlarger with a non-standard mount.
My current thinking is to perhaps go with a 35mm only enlarger that's in good working order as it would cost less than darkroom hire for a single day, and keep an eye out for a good lens. Then I can bide my time waiting for a longer term model to come on the market.
I'm hoping to relearn darkroom at a workshop next month so I can spend the intervening time hunting around and doing some more research.