Twin Scroll K04 are better at keeping EGT's lower than K03 --- K04 can run 280+ bhp Stage 1 without the need of a larger unrestricted DP, check the EGT's running a K03 at anywhere near that power with pre-cat in-place.
That said, removing the pre-cat can only be a good thing for lowering EGT's on both K04 and K03.
You could look out for a standard system on ebay or on here, and smash out both pre-cat and cat for some extra flow.