I think you want to open Island/CM regardless of your plan, which I'm happy to let my shuffles determine for me: since there's no way to consistently get more than 1 Province per turn or any super combo, I'd just be buying the best card I can afford each turn, which might lead to the Herald plan but I'm a bit sceptical about how easy it is to get two TMs in your discard in a reasonable timeframe.
Actually even when you buy candlestick makers at turns 1-2, copper at 3-7 then collision on turn 11 is almost certain, just buy 8. treasure map, 9. treasure map, 10. herald with 2 overpay, 3 coin tokens equalize estates and forth gets to 6 on turn 10.
With two coin tokens and practically any deck a sequence tm, tm, herald on forth shuffle should work unless you hit 2-3 on turn 10. If you need use coin token for treasure maps, it means its because of two estates and you wont have problem on other two turns.
That is bit ineffective, you could try buy one map on second/third shuffle and try collide it earlier. You could also use trick if one map is in discard and one in deck then overpaying herald by 1 would work too.
Island on 4, Merchant Ship on 5, Gold on 6, Masterpiece on 7 is probably best, although that sounds so boring that I might well end up buying a whole bunch of Heralds anyway and then shake my head afterwards, wondering what I was thinking.
Island conflicts with herald/tm as you need 15 cards for that, overpaying masterpiece on 5+ helps that.
Advisor is great support for the Treasure Map plan, at least that's what he once whispered in my ear.
I did not realize before that in this board advisor is a good idea. Again herald is key and it leads to interesting mindgames. You should try to play it until there are 5-7 cards remaining in your deck. For opponent correct move is to give you a treasure map. If he discards it and you had one in hand or discard then you pass and next turn overpay herald by 2. If you did not have treasure map you overpay herald by 1 and also collide map next turn.