I have the Ford motorsport manifold and have never heard any problems with it cracking, with it being mild steal instead of stainless it's less likely to crack if anything.

I have the below mods (see sig) and it goes like absolute stink it comparison to standard. According to Rob@SCC there's no performance gains in live mapping/different Bluefin map untill you change the OE turbo. Just make sure you get the de-cat file version as it keeps the engine light off, de-cat is a must. One with my mods apart from K&N has been rr'd at 290BHP, seems alot to me but I would expect 280BHP. Pro-alloy charge cooler next.