Dean Edge 4 pickup replacement

EMG 40 series are 4"
EMG 40DC, CS, and Jazz have full-width rails inside, so will work with 4, 5, and 6 strings (narrow) and active..
EMG-HZ are the same, but passive.

 

If the bass is comfortable, and plays right for you in every other respect, then you can look for an electronics swap. If you'r unhappy with the feel, weight or ergonomics of the bass in any way, then maybe look to change instruments entirely. That being said....

For metal? Go for those EMG DC pickups in the 4" size.

After you do the pickup change and live with ir for a bit, if you feel like you need to swap out for another preamp, Aguilar, Nordstrand and EMG all make units that would be dynamite with the EMG DCs.

 

The BTS is an EQ/preamp/buffer, as is the BQS, but the BQS has mids control if you think you'll need it.

 

Simply, that's what it is/does. EMG DCs have relatively high output, and several people have mentioned clipping issues with them, but IMO (w/ EMGs) there's no need to keep the bass vol fully open when it's plugged into an amp as the amp can be cranked to wherever. Active (low Z) pickups don't suffer from the tone drop when the vol is rolled off like passive (hi-Z) pickups, so they don't need to be run WFO on the bass.
Another thing that can cause clipping is adding too much bass boost (at the bass) to an already hot pickup signal. Better to cut the ranges less desired (leaving relatively more of the desired ranges), then turn up the amp.

 

Yes exactly.

Solid choice for your musical goals!

See if 9V works for you first. I ran an EMG pickups + preamp (J pickups and BQC system in my case) for years, and I didn't honestly find any difference running it at 18V. It's very easy to add a second battery if you need it, with no changes required to the setup.