If hydraulic brakes are akin to butter
Properly setup BB7's are akin to "I can't believe it's not butter" margarine
Personally, I think you should spend some more time getting frustrated with your BB7's. You'll likely have to do some caliper centering, maybe some rotor straightening but once they're dialed in they WILL work really well. If your getting alot of lever flex when you're really squeezing the brakes it's is likely two things. 1. your inboard (stationary) pad is dialed too far out from the rotor or 2. your cable housing is compressing, replace with a lower compression housing. Also, lubricating your cable will give you more more of that butter smooth action that you're looking for. Just don't use butter.
Also, changing to hydraulics will not guarantee less squeal, I have a set of stroker trails that just love to sing in the rain or shine.
Deep.