Audiophile Surge Suppressor (and nothing else)

I'd look to Furman.

ZeroSurge is not a conditioner AFAIR, and there were some clones under other brand names. (Non-MOV). I use it to power my vintage QUAD loudspeaker, which requires voltage (a lot) to be on for 24+hours. I never unpowered it. 

I don't like those plasticy cheap surge strips. The power strip I bought years ago (NAIM promoted) had no on/off switch. It is currently in use after a transformer that powers a pair of ancient mono tube amps designed for Britain. Doubt it is even a surge protector--just a high quality outlet box (with removable cord). 

@whart +1 on ZeroSurge. Similarly Brickwall or SurgeX

@zlone  You're correct even if you have whole home surge protection (I do) the electricians still advise other surge protection at the equipment.  I've had lightning strikes powerful enough to take out the whole home suppressor at the panel 3 times, though it did its job preventing any damage to the panel or otherwise.

check out Tripp Lite isobar has only noise canceling 

I second Trpplite. I've used their surge suppressors for years, after a whole-house unit at the breaker box. Make sure to follow through on your excellent idea of metal boxes, because T sells both metal and plastic.

ALL electronics in my house are protected by Tripplite or an isolation transformer. Tens of thousands of $ protected by some hundreds of $. Makes sense to me.