It all depends on what *you* want to do with the character. Do you feel more like a rogue, or more like a spellcaster?
Also, are you going for Arcane Trickster? The requirements are specific enough that your path is pretty much laid out for you in a lot of ways.
Only experience I have playing something like that is the one time I played a RogueX/Sorcerer1. Quarter-kobold, of course. The Sorcerer part was there for Change Self and the occasional Silent Ghost Sound. Fun!
I think that in general, unless you're using the Monte Cook sorcerer (which has some good bennies), if you plan on having more than one spellcasting level you want to go wizard. Sorcerers get their next-highest spell one level later. That's bad in general, and for a long-term multiclass character, it's even worse.
Assuming you don't want to go Arcane Trickster, but want more than one level of spellcaster, I'd go Rogue/Wizard. Won't be powergamey, but could be fun. Your attack bonus is going to suck, though
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