Your new 3KVA UPS and dedicated circuit (assuming USA) will likely use a NEMA L5-30 plug on a 25Amp circuit breaker. Make sure you have the breaker box space and the budget for a little electrical work.
Your systems will be safer than on wall power or surge strips. If you purchase and properly configure all your systems to shut down on command, you will be orders of magnitude safer than wall power/surge strips. In my opinion, it is easier to properly configure a bunch of computers against one large networked UPS than a dozen combined USB and networked little UPS's.
Your systems will be less vulnerable to user related circuit breaker trips than if you use multiple small USP systems on existing premise 110V wiring. This is because almost all wall circuits are shared with lamps, other computers, and who knows what, and you only find out what all is shared when the limit is passed.
Having a dedicated circuit is insurance that no one else will be plugging a toaster or hair drier into your circuit and bringing your computers down! Even with shutdown properly configured, you still have to reset the breaker and boot up again, minimum 1/2 hour time lost, usually more.
Having said that, the quality of your UPS is paramount in handling anomolies- such as passing along lightning strikes. Buy a good brand name with a warranty.