Are you looking to record digitally direct from the desk up to a maximum of 16 channels? If so then it probably is a Mackie Onyx with Firewire that you want... unless you can stretch a bit more and get an Allen & Health R16.
But if you want a desk with multiple outputs in analogue then the A & H ZED 420 might fit the bill - available for £749 from Andertons.
Or you might look at the Phonic Digital Mixer... but I'd be a bit nervous about build-quality - never having seen one!
The older I get, the better I used to be