siamese ports generally aren't a good idea, i think you'd slow down airflow and create too much reverse flow (heads do flow in reverse too) for it to have any decent real world application. look up anything about minis or early holden sixes, with siamese ports, they suck
direct head injection (like a gze?) is a good idea for economy and atomisation, but you can get more power by boxing the whole intake and mounting the injectors spraying straight into a dcoe-style throttle body, before the butterflies, strange but true
if you were to spend the money on a piece of alloy to make your own K head, the billet chunk would cost more than an entire 4age motor. and you wouldn't make a head anything like a 4k head, you'd make a twincam crossflow 16v/20v head with inserts for the combustion chamber. i remember reading about one like this on a drag bike, the head cost about 40 grand
unless you have the bits laying around and can do it all yourself, a K motor is just not worth this much effort