As title states which is better ??
BTW this is for my brothers aftermarket turboe'd 100 series
any advice appreciated

Denco Diesel do a really nice air/water kit for the 100 series. Probably a better solution than an Air/Air on a heavy 4WD diesel. I have a Safari air/air intercooler on my factory turbo 1HD-T Landcruiser, cost a fortune and did bugger all. 3 Inch exhaust cost a third and made more difference. The Denco kit is vehilcle specific and comes with all pre-cut mounting brackets, electric pump and the lot.