Si and I discussed this the other night. Worked out with all the costs its just not worth it, cause the 160 isn't that much faster than a VI. Might as well leave it on ebay. You firstly have to make MEMS3 fit your wiring, which won't be simple as its not plug and play to the mk3 loom. Then you have to get MEMS3 to give a signal to the clocks for the milage (you'd need 160 clocks then). You also need to feed the ECU with a second lambda signal.
Its just too much worth, for little performance gain.
Steve