Where's the best places (quality & prices) to get the following parts

Cylinder Head (With or without cam & rockers, since i have a brand new cam & rockers)
Full Engine Gasket Set
New Injectors & Gaskets

My engine block is at the machine shop right now, getting hot tanked, bored, ect. But my head is cracked (found them when i was cleaning it) in each of the Injector "inserts" 2 are pretty nice sized cracks, and 2 are just starting to crack.

And i'm questioning the condition of the Injectors, since a previous owner of the engine swapped in whatever would fit apparently (3 injectors have the same part number, 1 doesn't match them). So since i'm doing a complete rebuild, and have to replace the head, might as well replace the injectors too.