The Impax generators on screwfix are good VFM – I picked up the 2500w one for cheap on ebay (discounted because the panel with the switches on was printed upside down)
The sine wave / suitcase style gennys can be handy if you use anything sensitive – my circular saw has electronic speed control and it won’t run off a bog standard genny, some chargers and anything else with electronics in, charging your phone even, can be a problem with regular portables. The sine wave ones are also nice and quiet.
I bought mine as sine wave ones can be tricky to hire when you need one and as well as power tools I used gennys to run video projectors and the like that are easy to upset if the voltage and waveform aren’t good