Its quite easy getting 400/400 from a boa.
Its safer going more 350/350 on the standard engine but i will be outting forged pistons in as this is the weak point really.

Essentially you just go either single or twin turbo with all other bits.
I already have the standalone ecu so just need to get manifolds and all ancillaries then just mapping.
I think it will cost me around £1250 to get about 350/350