I dont believe anyones tried this but its alot of money to throw away if it does turn out to be rubbish.
Theres no denying its ALOT of kit for not alot of money (£643), but that makes me wonder about the quality your buying at that price. WEPR & Zisco for example sell there kits higher because there designed and made to a high quality, tried and tested also.
Its a risk you need to ask if you want to take really. I think the Manifold will crumble but i could be wrong. You'd normally pay the price of that kit for a decent manifold.
Iain