Scirocco Central

I'm pretty sure that my car is suffering from carbon buildup on the intake valves - rough/lumpy idle but stable rpm, intermittent loss of power while accelerating, no CEL, coming up to 60k miles. Does anyone know of places in Scotland (preferably North East) that offer carbon cleaning, either manually or by using walnut blasting? I'm reluctant to go back to my usual VAG specialist as when they checked the car last month, they just said they found no error codes or leaks and didn't believe anything was wrong with it.

Have emailed the following places so far:
-VES Sport, near Dunblane
-Star Performance, Kirkcaldy
-Autohaus, Edinburgh
-Ayrshire BMW and Mini Specialists, Ayr (answered saying they won't work on VW cars)

Any suggestions much appreciated, thanks.

Update:
VES Sport, near Dunblane - no response
-Star Performance, Kirkcaldy - £299 incl. VAT
-Autohaus, Edinburgh £270 incl. VAT

I went with Autohaus in the end and they did a great job. The guys there were a pleasure to deal with and took some before and after picture of the valves. They removed the intake manifold and used a combination of walnut blasting and manual cleaning with brushes etc. Car is running much smoother now and no longer jolts under acceleration.

Before: After:

good work!

I think this is something everyone needs to consider

Guys at the garage said they are doing this on loads of cars right now.