Unfortunately its alot of work to put a Ph1 throttle body on a Ph2 inlet, requires drilling a hole and tapping a thread IIRC. You cant just put the ph1 inlet on either as the breather plate on the top of the rocker cover is different also, and im not sure if they are interchangeable (dont think they are). JamesR5GTT put a Ph1 throttle body on his Ph2 engine, but it was a lot of work!
At the end of the day if you're going to throttle body a 1*2 engine and put it in a Mk1, any engine would be fine. But if the engine is retaining the standard inlet, Ph1 is what you need (Also not to mention the Ph2 loom is no good nor is the Ph2 ECU's, has to be Ph1)