Companies I know that can do it for definite are Abbey Motorsport & Horsham Developments, the latter being the garage who did my Zed. There are other companies available like Tdi North & more etc who will also be more than capable of doing an FI build.
Cost effective? Well I think you're talking about a package deal like some of the traders on here offer for the Vortech V3sci kits. Obviously secondhand would be even cheaper but then that's always a gamble with using secondhand parts imo.
I'll PM you some prices etc from when I had my Zed done. You can then print it off for your mate ~ I'm assuming he's after charging a Zed is he?!