tapping the oil pan a must?

If you turbo can you use this:
http://www.daytonimports.com/Merchant2/merchant.mvc?Screen=PROD&Store_Code=DIC&Product_Code=GETOFK&Category_Code=GE

http://www.daytonimports.com/Merchant2/graphics/00000001/turbo.jpg

and avoid tapping your oil pan? Does it work well?

Yes you can use that but you need to email Goleneagle and see if it has a tap to return the oil. I know it has 2 to supply oil but not sure about returning the oil. Email them and see.
If not then find someone who is parting out a B18C5 and get the oil cooler from it and use that, it sdrews on behind the filter just like that but it has a place for supply and return.