You have to think about death, and the possibility somebody will've broken your bed. Nice tower you've got there. I'm assuming it doesn't touch the ground, so teleporters or arcane levitators seem to be the way to go. Or aerial faith plates. Long distances are definitely railcraft though. Unless you have tons of EU.
Or have a vanilla idea, and make yourself a TNT launcher. A TNT elevator. A TNT player-shooting device. They exist, and they should be fun!
Gunpowder and sand shouldn't be problems. Especially on servers, you can probably expect SOMEBODY to have a creeper farm. And sand? Pfft.