Sorry to not answer the question but is there a reason you want made to measure? Buying off the peg has many many advantages, and then you have all the bench made options available - deepening a rear gusset, lengthening a flap etc. All you need then is a good fitter with a brand that may work. Much less risk.
Just have a somewhat rotund HW coloured cob was wondering if getting something made to fit her would be the easier option. The saddle I am borrowing at the moment is my friends retired boys made to measure and i was looking to get something similar made with the addition of knee rolls lol x
Then if I may can I point you to my colleague Diane Smith at Native Pony - we have two jumping models that work for the wide and flat - www.nativeponysaddles.com. Otherwise a company like Ideal or perhaps Black Country may well have something to suit. Many will recommend Saddle Company but personally I find synthetic trees are not as stable on very wide horses, and they can perch which also means instability. I guess it depends on the fitter.
Sorry, I assumed close contact meant jump saddle, as you will see, between our two ranges we have plenty of GP and WH/showing type saddles for wide types as well!
Not sure where abouts you are but I had a saddle made to my exact spec by Rushton saddles and the price was reasonable imho. I had tried about 30 saddles and couldn't find anything to fit both me and ponio.
Would advise Alene at Strilingshire saddle fitters they will template your horse and have a very nice mono block saddle they call the patriot .Pm me if you would like her contact details.