Temperature Control

[Dr Horrible]

A cooling coil or thermowell might be a better option, but honestly I don't see myself replacing the fridge.

If I was in your situation I wouldn't change either! - I suppose I'm just putting across the case for anyone who doesn't have the space for a fridge that a cooling coil is an alternative that would work.
Your point about the mixing is a good one - things are pretty active in there ok, it's just that the last few brews where I've had temp probes in both the centre and the wall, during the really active time the probe in the centre was going mad whereas the one on the wall was just sitting there not doing much, there was a couple of degrees of a difference between them for a while before they balanced out when things calmed down.
I'm a bit of mixing nerd, I'm sure someone has done work on temperature profiles in a fermenter somewhere, must go and have a look.  I have a hunch the mixing may be great from the top to the bottom of the fermenter but possibly not so good sideways  - from the centre to the wall.  I'll get back if I find anything interesting - in the meantime you just enjoy your nice fridges! (grumbles to self)

[imark]

I have a few kegs that I'll eventually get round to cutting open if they'd do the trick.

I intend to do just that. A single chiller should be able to maintain different temperatures on different vessels using solenoid valves.

[Will_D]

Or I could buy this. http://www.a1barstuff.co.uk/single-cooler-p-400.html 

Buggeration!

Thanks Thomas - that link will probably suck even more money out of me!

Great range of Stuff! Its now in my address book!

Many thanks