[ZeroID (Brent)]

None of your gear list has critical sine wave requirements that I can see. They all use DC PS's in between the AC anyway so simulated sine is not passed through to affect devices.
Just ensure you have enough capacity on the UPS to deliver your required amps for your required time frame. Most UPS's are designed\specified to run long enough for a graceful shutdown on a server or PC and will require extended batteries for longer run times.

Good move on the replacement program, the electronics on these do age as they always have some load on them and the conversion hardware has also become more efficient.

My wife is the Branch Manager for UPS Power here in NZ selling Eaton UPS. We run a double online conversion 3kw unit on my sound system. Gets rid of all the annoying pops and crackles from the mains AC lines.
Makes for GOOD sound.

EDIT: Your normal UPS for PC use is only in a standby mode during use. It will be filtering any AC and giving some protection but the equipment will be only seeing normal mains AC unless power goes out. Then it will see UPS approximated sine to the DC PS's.
Only a double online conversion UPS ( AC > DC > AC ) as I use on the sound system supplies all AC all the time.