"Soapbar" Pickups are so-named due to their resemblance to a bar of soap and originally referred to the Gibson P-90 guitar pickup. The term is also used to describe any pickup with a rectangular shape (no protruding screw mounting "ears" like on P, J or MM pickups) and no visible pole pieces. Most of the pickups falling into this category are humbucking, though a few single-coil soapbar designs exist. They are commonly found in basses designed for the rock and metal genres, such as Gibson, ESP Guitars, and Schecter, however they are also found on 5- and 6-string basses made popular by jazz and jazz fusion music, such as Yamaha's TRB and various Peavey model lines. 'Soapbar pickups' are also called 'extended housing pickups', because the rectangular shape is achieved simply by making the pickup cover longer or wider than it would have to be to only cover the pickup coils, and then the mounting holes are recessed inside these wider dimensions of the housing.
Trigger pads and drums, on the other hand, when deployed in a conventional set-up, are most commonly used to produce sounds not possible with an acoustic kit, or at least not with what is available. Any sound that can be sampled/recorded can be played when the pad is struck, by assigning the recorded sounds to specific triggers . Recordings or samples of barking dogs, sirens, breaking glass and stereo recordings of aircraft taking off and landing have all been used. Along with the more obvious electronically generated sounds there are synthesized human voices or song parts or even movie audio or digital video/pictures that (depending on device used) can also be played/triggered by electronic drums.
Since there are so many digital pianos worthy of your attention in this catalog, you may want to narrow down your choices using some of the search options on the sidebar. For example, if you select stage digital pianos under the category section, you'll be presented with all the digital pianos that were made for the stage. Once here you have the opportunity to drill down even further and can search by topics like number of keys, MIDI/USB Connections or by whether or not the digital piano has built-in speakers.