I have the original oil seperator tank unit on the engine..
I slightly overfilled it the other day and it blew a crap load of oil all over the bay!!
I figure .. 1. Do not overfill engine & 2. I need a vapour oil catch tank now...

Will this one be ok Subaru Impreza P1 RA GC8 Oil Catch Tank Silver Small | eBay

Any pointers aprciated ..

That looks fine and very cheap. I made one from an alloy drinking bottle cost about £4 but at that price go for it.

At that sort of price i can justify a nice shiney item as opposed to
'what I might make out of whats knocking around in the shed' ..
cheers..

[Edited on 7/3/12 by johnemms]

Al little bit dearer, but still a lot cheaper than an alloy one from the likes of demon tweeks
http://www.alloyracingfabrications.com/1-ltr-alloy-catch-tank-1.html
He makes the pipe sizes (and counts) to your specification, and it's good quality.