SCM on a Sublime Chord + Truenamer 11? You can get full 9th level casting that way, I think. And no, you won't be any lower than Tier 2.
And you can still add Spellguard of Silverymoon for the cookies, along with Magic of the Land.
That said, why not just a real, optimized Truenamer? It's more or less a Tier 3 "spellcaster" done that way. Especially if you have an awesome DM that lets you use Ultimate Magus with it + Wizard (Tier 1, though).