well i bit the bullet and i purchased my kit, cost me about 750 but i purchased a daughter card that was allready included, a couple thing's i orderd double like boost control mod kit and vtec controller (they say you can use it to control a relay, so i was thinkin of like a main relay or second fan for a/c.)
i've wired up my board to run msii V3.0 extra 2.0.1 code, and have 6 db373's (newer coil drivers replacing the discontinued vp293's) driving 6 1jz coils, stock cps, q45 tps. im not sure on which idle valve i should go with but wired it up to use both, or should i say i have down the flyback circuits for the pwm set up, but left the idle circuit half finished. so i still have my choice.
i have built my coil harness and still need to build my engine harness, but my plan is to attempt to make a fields style harness to connect the msii to the stock 89+ harness, i have found parts supplies for all the connectors, but the ecu connectors are on back order for another 7 weeks atleast.
still looking for earily modle ecu plugs. but if needed i could find the stuff in junk yards and make pre89 harness for people interested.
please note, that using your stock harness may also including any electrical problems you have.
so far form all the reading i have done, the stock cps should work, but people are having "noise" issues, or crosstalk from G1 and G2 causing count re-set.