B18PoweredCivic

Heres the situation...friend of mine had a greddy sohc turbo kit for $650...I have a 96 civic with an LS swap...His kit includes D series Manifold, Turbo, Downpipe, Piping, BOV, and Trust Intercooler..He told me the turbo has an INTERNAL WASTEGATE..Whats the difference Between INTERNAL AND EXTERNAL Wastegate?...Also I was planning on buying a B series Manifold and bolting it up with the kit...If i buy this manifold will everything work..He said he will include some lines and stuff...What do you think..let me know if its work it..Also will the Downpipe work with the B series manifold?...Thanks alot