If you're serious about this stuff, in the strongest terms possible I recommend you pick up Dickason's "Loudspeaker Cookbook" and D'Appolito's "Testing Loudspeakers". They will disabuse you of any notion that a proper crossover can be either 'off the shelf' or 'textbook'. I believe they are both available from PartsExpress.
I started from scratch, without much knowledge or experience, on my first multi-way project almost a year ago. I'm still working on the crossover...
Regards,
John