Well, the less Things in way of the speakers, the better. So if you can find an active HU, that has it's own adequate EQ, that'd be the best case scenario. Pioneer 80prs, Pioneer P99, Alpine 9887, Alpine 7998, Alpine 9813, Alpine 9855, Eclipse CD5030, Eclipse cd7100, Eclipse CD7200 Mkii. There's no such thing as an "active driver". Every driver is a driver. The drivers you have right now would work fine, you just remove the passive crossover. The benefit of running active, is you can piece together your own component set if you'd like. So if you were to piece together your own set, you'd be looking at "raw" drivers. Drivers sold separately and individually.
Parts Express: the #1 source for audio, video & speaker building components and
Madisound Speaker Components: distributor of loudspeaker drivers and parts for speaker builders. are good places to look for these DIY speakers. Most decent tweeters starting at $20-$30 a piece. And mids usually around $50 to be safe. Some can be cheaper. Many can be MUCH more expensive. Keep in mind, you don't NEED new speakers. You can still use the ones you currently have, you just remove the passive crossover.