You know, modern Jeeps have disc's up front, and the only reason they aren't on the back is because of cost-rear disc's with a parking brake setup are more expensive to produce. As for reliability-What do you mean, drums are more reliable than discs? I Think Not!
Also, please, don't add air to your hydraulic lines because you are just disabling the brake by doing that. The end result is spongy at best, no brakes at the worst. The feel you are looking for sounds to me like you want the lever to travel a long ways and gradually add pressure and stop just before bottoming out at the bars. This is easy to achieve with cable brakes-hub or disc-because the cable will stretch somewhat and give you that feel you like. However, hydraulic disc's will Modulate Just As Well as your old cable brakes, the levers just don't travel as far and they don't feel spongy like a cable does. The other big advantage to hydraulics is the power factor, two fingers all the way down the mountain-- couldn't do that with any cable brake, my hand used to go numb about half-way down! I think you are just so used to that particular feel that other systems don't seem as good to you, when in fact they work great, just don't feel the same. And we, as humans are prone to like what we are used to more often than not!