There is a mega thread under my name if you do a search.
Very nice basses. The Update models seem to be the most popular. They are heavy, and very 'active' sounding. They are meant to cop the 'jazz on steroids' Marcus Miller type active J tone, and they do it well. Huge low end and sizzly top end. The other models (classic, etc.) are more 'passive' sounding.
These basses have REALLY gone up in price. I just sold my 5 year old Update 5 for almost $4K. The new ones can go for well over $6K US now, which IMO is a bit ridiculous (I don't even want to think about what a fancy top would cost!).
The bad news is that Chris is very hard to get hold of, and his customer service is among the worst in the industry. Time from order to delivery can be years. Even though you are in the UK, if you are interested in one of these, Glenn at Austin Bass Traders (Texas, USA) is probably the best bet. Glenn has Celinders on order, and if he has one that you like, he has them coming in every 6 months or so.
I would HIGHLY recommend taking a look at Sadowsky, Alleva, Nordstrand, Lull and some other companies that also make great boutique J's and have the reputation for a bit better customer service (especially if you don't need that 'super on-steroids Marcus' sort of vibe). All of these basses are between $3,000 and $4,500 with the options you mention in your post, with the Lull at the low end of that price continuum, and the Alleva and Sadowsky NYC at the upper end.
IMO and IME!