Tom Lyon will probably chime in here later - he has a fascinating, albeit not inexpensive, inverter solution that would work but the cost may be prohibitive.
Typical home computer inverter UPS's are very noisy & are not what you want here. A quieter model may be OK for your low current pre/proc, but not for the whole rig. I can't recommend anything specific though.
Regarding line-transient protection; this is definitely a good idea anywhere, but especailly for your situation which is not unlike my own. There are numerous workable options. Many line conditioners have integral surge protection, but you would need to chose one within budget & that won't constrain your power amps' dynamics, & will not adversely affect desirable sonic characteristics. This can be difficult. A Chang Lightspeed 6400 or 9600 may do it for you. PS Audio Ultimate outlet also (I believe) has surge protection (better verify that however). So does Audio Magic & no doubt there are many others.
Or you can get AC outlets containing MOV's (metal oxide varistors) MOV's are surge arrestors. Or you can install your own MOV's across your outlets if you're skilled electrically. GE V130LA20B's are what I use, combined with a line conditioner. Whole house surge protection is also a good idea; a large arrestor box installed typically at the breaker panel. Surge-X is one model available from member Chichiuno. I use an industrial model Joslyn gas-tube-discharge whole house protector for that. There are others too, but the inexpensive carbon block arrestors are only good for preventing house fires w\ direct lightning hits & won't prevent your audio rig from failing due to large line transients, so get a good one if at all.
