dont cut the cross member
unless you intend on fitting or fabricating some type of plate to re attach afterwards ,as you will weaken the strength of the chasis no end
as regards front mount, what boost you intending to run, what hp, and what size turbo? huge core areas,and boost runs will take more to fill, ie an almost standard t2 turbo wont do the system justice, the gt breadbin is a good comprimise on anything up to 18- psi on a t2 standardish unit, if youve got bigger and intend on running more boost/power then aim for as gooder core design as your money/budget can afford, as it will pay for itself in respect to performance per psi,
dont run one myself,but loads of members do, and im sure most will put some imput towards whats hot and whats not