He means "save a bit more" as in save a fucking shitload more. Turbo will suffice nicely on it's on. If Ian Howell doesn't need both on his monster, neither will you. There was a company that did a drive in drive out low pressure turbo conversion for under £2k a few years back (may have been PE). To do it right will cost a fair wedge of cash.

Before building make sure you can insure it.