LS twin turbo advice needed

[DangerousDerek]

After years of successfully drag racing in my Rover V8 powered TVR the time has come to take it to the next level.

I want to fit an LS motor and use a turbo or 2.

I am considering using the LQ4 6.0 iron block.
To fit a single turbo up front that is big enough might prove to difficult to package so thinking using twins.
The aim would be for 700 bhp as a starting point with scope to 1000bhp.

Any comments, recommendations gratefully received.

[DangerousDerek]

I haven't got an engine yet.
I thought going to 1000 might be pushing an ally block but will keep my options wide open thanks.
A single would be nice, I need to start getting things mocked up. One person has told me its too difficult but that sounds like a challenge to me.