https://www.dtmparts.com/kit-echangeur- ... 2x30063177
They are made of aluminium and well finished (much less prone to leaking than the originals). They are slightly bigger (2l more) than the oems but less than the Wagner's (3l more) and require a slight adjustment of the air ducts.
You could probably get them directly from the manufacturer (ta technix), but at 600€ delivered to your door, it seems a very good alternative. Import taxes may be applicable to the UK though.
