If you can dump 2 feats I think you can access SC a level early through the Favored Contact thing. Any PrCs whose class features are the important thing go before SC, because the only thing is that their casting progression doesn't contribute. That leaves 4 levels of Anima Mage before you could take Sublime Chord, given the original build. Haven't got time to number crunch, but I think the best option MIGHT be dipping a bunch of classes with casting instead of UM, if you don't care about slots per day; each one adds your SC caster level again to your total, because SC drags it up from 1, which is a bigger bonus than UM provides, I think.