I was able to find some info about the Mattel Sizzlers, this is indeed a cool idea for micro RC!
Do you have more info about what they're called at Target?
If you need more power at the 1/64th scale, you'll have to dig into the guts of the cars and upgrade/mod them. Dual-Cell, LiPo and such upgrades have been done and will probably achieve what you're looking for.
If you want to step it up to the 1/43rd scale, then you're talking about the Epoch "Indoor Racer" (You'll want the spec-2). I'd be willing to wager they'd have the juice needed right out of the box...But that 2" limitation takes them out of the running.
Please do give more info though, you've very much piqued my interest!
