Id ' go for the cheaper petrol-powered generators . There appears to be a really cheap series of 220 petrol generators (small , blue , branded "Tiger" in Gambia , and Einhell in EU) which costs around 90 Euros in the continent (so in UK should be not less than 300 UKP !! -ha ha -
, and produce around 800 Watts . Sure , you need another smallish fuel container , but on the other hand you have 220 volts aboard ! (enabling to use a serious and cheap air compressor , , standard TV , lighting , a propper Battery Charger ,and only god knows what else can it power during a expedition.
On top of that , I can power a Arc/Tig inverter welder (another 100 euro) with unlimied field-uses in a LandRover
Mine is so small that the generator AND the welder both fit in the box beneath the right seat in a Landy.
Hava nice day.