In addition to the inversor (mentioned above) do you also need an UPS box like (APS, OMEGA) to protect against power surges?
Temporary power and surges are two completely different issues.
All electronics must be so robust as to make surges generated by a UPS (in battery backup mode) irrelevant. Go back and read those numbers (ie 270 volts). Why are spikes and other anomalies generated by a UPS potentially harmful to small electric motors and power strip protectors? Because electronics are so robust as to make those anomalies irrelevant.
Computers are required to operate without any interruption for 17 milliseconds. Many will work much longer. Whereas a 20 or 30 millisecond delay by the 'whole house' inverter is technically bad, some computers will still work uninterrupted. Does not matter. The numbers say that 20 or 30 millisecond delay is too long. So the cheapest UPS with the dirtiest output (that takes about 10 milliseconds to switch over) should be sufficient.
Also grasp what eddy has posted. Inverters can output very 'dirty' power. A UPS is often made as cheap as possible. Therefore can be confused by dirty power; would quickly discharge its battery. Unfortunately, most UPS manufacturers will not provide numbers that quantify that problem because they quietly expect AC power to be so 'clean'. On site testing may be necessary.
Above is temporary power. Surges are something completely different. Most all surges are made irrelevant by how electronics are designed. Your only concern is the rare surge that can overwhelm protection inside all electronics. If that surge is earthed before entering the building, then nothing is damaged. Otherwise that surge goes hunting for earth inside and destructively via appliances. That surge selects which appliance to damage.
Nothing on an appliance power cord will do better than what is already inside. So that superior protection is not overwhelmed, you must earth every wire inside every incoming cable. For example, if AC has three wires, then all three must connect short (ie 'less than 10 feet') to earth. One makes that connection directly. Other two must be earthed via a 'whole house' protector. Protection is not the near zero component inside a UPS. Protection is a dedicated and low impedance ('less than 10 foot') connection to single point earth ground. Only the earth ground does protection. Protectors either connect short to that protection - or do virtually nothing.
Protection inside a UPS is near zero. Just enough above zero so that advertising can hype massive protection subjectively. Temporary power and surge protection are different solutions to two completely different problems.
Having said that, sometimes an inverter at the service entrance already contains a 'whole house' protector. Therefore that inverter must make the low impedance connection to single point earth ground.