Hi Moony - Do you want a brick oven, or would you consider a modular cast oven? Did some research on this recently for modular ovens.
The Stone Bake Oven Co do some good ovens and are very helpful on the phone.You don't need to build a concrete foundation for their smaller ovens. Dragon Ovens I think are a relatively new outfit who used to supply Forno Bravo Ovens in the UK.
I'm sure other members will be able to suggest alternatives.
I've just built my own cast refractory oven - which took up a lot of time. These builds are time consuming projects - If you employ a builder to do it, with the cost of materials and labour, you will probably spend the same as you would on a modular oven.
Vitcas, Kilnlinings, Jamie Oliver, are others off the top of my head - Google is your friend.
What to look for with the modular deals:- - Ideally to want an oven withe the flue OUTSIDE the dome, for more efficient heat retention. - The insulation is expensive stuff - make sure it's included in any packages, or account for it in your budget. I would say minimum 2" insulation board under the oven and 2" blanket over the oven. (mine is 3+3). Don't skimp on insulation, especially under the oven. You can always add more over the dome if required, but the insulation under the cooking floor is there to stay, unless you want to build it twice. - Thickness of oven dome and floor. The thicker the material is the longer it takes to heat up, but if well insulated it will stay hot for longer. Thinner floors and walls will heat up quicker, but the floor will lose heat quicker through cooking. It's your choice. The modular ovens still aren't cheap though, do not include assembly labour, or building the base +stand if required.
If this helps - I've just built my own oven in cast refractory.
Internal diameter of oven is 1 metre. Dome walls are 4" thick. Fire brick cooking floor is 3" thick. Dome insulation blanket is 3" thick - Body soluble blanket. Floor insulation is 3" thick Calsil board, on 2" vermicrete.
It's quite a high spec compared to the modulars I found, especially in terms of insulation. With the 7" vitreous flue pipe, a thermometer and some fire cement(still have to make a wooden door) - As a cost comparison I spent £900 on these materials. All the items above are what you would expect to see in a kit (specs vary).
This does not include the base, stand, vermicrete insulation layers, decoration/render since none of the kits do either. Including the brick stand, it's taken 4 weeks (solid) to a working oven . Some pitfalls and a lot of work, and if I had to do it all again, I might consider the extra £1000 or so for a modular oven with uprated insulation. But I have enjoyed it. See my build so far on this linky:-http://ukwoodfiredovenforum.proboards.com/thread/1754/refractory-first-build-advice-welcome