Hi Scott
I'll send the feelers out on the Jubilee and see what comes back.
Have you done the right thing with a 10mm kit? Yeah, I think so - you couldn't have got 1/32 kit for the price you are paying and Barretts deserve their good reputation. There is the odd bit that needs thinking about but thats true of just about any kit loco in any scale as the build threads on this forum testify. If you are interested in building, making and operation then don't have any regrets, just enjoy it for the experience.
In terms of 10mm BR Mk1 coaches you need to add Peter Alliot Model Engineering to your list. I'm looking at a parts list from 2009 (I don't think he has shrunk his range since then) and can count 14 different MK1 specs (FO, FK, BFK, CK, BCK, SK, BSK, BSO, TSO, SO, RSO, RUO, RMB, BG) which I'm guessing would satisfy most of your requirements
If you look on my other thread, all the videos with my engine running are pulling Pete's coaches to give you an idea of what they look like (its only the chocolate and cream coaches that were 1/32 scale).
In some respects I guess you need to choose: are you building a train (or trains) ie matching loco and stock or do you want to have one rake of coaches and have multiple options for pulling them? Both approaches are common, some people have to accept that they own the odd engine that isn't the same scale as their coaching stock but it doesn't seem to spoil their enjoyment. Trouble is, that is quite a personal viewpoint and only you know whether you are happy in that situation.
I'm not sure what your local group situation is like but chance are there will be coaches for you to pull, a quarter of my running time has been spent pulling some extremely old wooden bodied maroon 10mm coaches - I haven't given a rats backside until now
By the time you have built yours and gained the experience of running it you will either be able to sell if for at least what it has cost and go 1/32 or you might just find that 10mm is fine when you are running.
I'll send you Pete's details anyway.
Steve