Courier looking to reclaim French, German, Dutch etc VAT

 A potential new client trades as a long distance courier and is looking to recover vat he has been charged, mostly on fuel, in other EU countries.

I believe that the reclaim is fairly torturous but can be done if the sums are high enough

I know that there are firms around who specialise in this sort of thing, indeed google throws up a few names. 

However I prefer to go with recommendations wherever possible. Does anyone know of a firm which is good and effecient at this sort of claim that they would recommend using.

Many thanks

Martin