Funny thing is most quality inverters are 350w minimum, so just go 350 and call it a day. They are the best balance between output and standby consumption.

My personal exp is victron phenoix 180va was great, built like a tank, victron make their gear big and heavy so they cope with the heat. Got the newer 500? And it's fantastic.
Also the redarc and cotex 350w work great, simple.
I also use a small 150 console/ coke can unit and it's seems OK for one of my induction fans, but the first unit was DOA.
I run up to 8-12 240v gadgets easily at a time like power hungry Thinkpad, induction fans that chew 60-90watts.
No way will I ever try running my laptops on 12v chargers, they are very poor quality with the wiring and the OEM make superior plugs and fittings. As far as 240v safety goes, you can still get killed easily following all the rules and with safety switches. I have up to 10 extension leads ranging from 1mm2 household duty all up to 2.5mm2 60m monsters, so keep the leads in good working conditions and carful of water.

Do you really need a licensed electrian to stand next to you holding your hand as you plug two double insulated (no earth pins) appliances into the one standalone inverter????