What Solenoid For Robot Drum?

So I'm working on an Arduino build that will take incoming drum hits (read via piezos mounted on a drum) and play back (via solenoids) patterns on the drum.

I'm thinking push solenoids, with a little head on them, similar to this: http://www.logosfoundation.org/instrum_gwr/snar.html

With push based ones I can simply have it 'poke' the head, and that's that. Rather than having a pull one mounted with a stick/lever.

I ordered a 12VDC Black Knight solenoid to test with. This one: http://uk.farnell.com/ped/120-420-620-620/solenoid-tubular-push-12v/dp/4207427

For one, it's tiny/wimpy. But beyond that, the plunger(?) falls right out. In the SNAR build linked above it looks like thats resolved by using gravity and a baseplate of some kind, but for my build, the Solenoid will be horizontal. I've seen some with springs in them, but after buying the wrong solenoid one time, I figured I'd ask around, before buying a wrong solenoid for a second time.

What solenoids are generally good for this kind of thing?

That's a good idea! I just through a push Solenoid for simplest setup (it 'poking' the head), but speed would be concern.

Are these kind of things available new, or do I have to try to scrounge up some surplus bells/buzzers?

In looking closer at this type of solenoid, I'm wondering if it's going to be able to generate enough force to make an audible drum hit. I would imagine it needs a certain amount of distance to generate enough power to strike a drum head. A hard bell, and a hard beater don't need as much momentum to be loud.

The diagram, and the ones you link look like they only move under a centimeter.