I fitted a new Britpart rad with plastic end tanks to my 300tdi a couple of months ago and seems to be fine .I was a bit unsure about the plastic bits but that was the cheapest option at the time as its my daily transport.
I did consider getting the old one repaired (new core,thats where the hole was, with original brass ends),which would have cost about £150 +vat at a local specialist rad place,which isnt a bad price.That would have been the better option and if i had the time and cash i would have gone for that.
So if you can get a new all metal rad for £99 I'd choose that ,or get the old one reconditioned from a reputable place.
In the words of the bloke at the rad. place " I wouldnt have any plastic c*** anywhere near my own car " !