Anything wrong with doing it this way?
Special
Detect Magic, +1 spellcasting level
True Spell (0th)
Metamagic feat, +1 spellcasting level
Spell Dilettante
True Spell (1st), +1 spellcasting level
Powerful Pressance, Metamagic feat, +1 spellcasting level
True Spell (2nd)
Knowing Stare, Spell Dilettante, +1 spellcasting level
Metamagic feat
Mastered Name, +1 spellcasting level
At level 20 (sor10/master10) you'll still have 8th level spells like before and it's more inline to the way they PrC's are currently written today.