the output used in the model number is usually the max output , the rated (continuous) output is lower.
for instance my suzuki 2600 efi generater has a max output of 2600 watts and a continuous output of 2200 watts.
As long as the continuous output is higher than 1800 you will be fine .
Got my generated secondhand on ebay for £80 , starts first time every time so worth a look on there if you want to save a fews quid.