you can always go the cheap route.
on a few ups. you can swap out the battery for a car battery
id recomend a sealed battery and preferable a deepcycle battery
make sure to put it in a container that could take the acid if it leads, a good idea would be to tie,glue or secure in someway that it cant be knocked over.
that will give you a good long time on the cheap.
as long as you get a good unit that has a good transformer that can up the voltage to either 110/230 depending on where you live