Sorry my bad, i completly missed this bit...
Considering how they've spoken to Sayathan I'd stay well clear of BBR and their conversions. If you want Turbo, the GTT's is far better.
Having said that if you want the best intercooler you want to look at the GRS intercooler and chargecoolers offered through an number of sponsers on here. A front mounted intercooler is also in deveopment but will mean ditching the air con.
However keeping the standard cooler and then putting the air through a second intercooler seems a bit daft to me!