If your truely ready to experiment, your selection of speakers will far out weigh (in sound quality / dollar spent) your selection of active crossovers. Once you have selected the speaker you want, for the sake of experimentation, find the most flexible active crossover for the money, like a Behringer or Rane off eBay for $150USD.
This will allow you to play with different xover points and slopes until you find what works best.
Than you can go looking for the perfect sounding active crossover.
Of course, than there's the amp selection.