Hi Goldmund,
One could probably debate 'but/however', and even, for different reasons, 'hopefully'. Here is only one resource on 'hopefully': http://www.bartleby.com/61/41/H0274100.html
It's perhaps, a nit-picky kind of debate.
EDIT: Here, I think 'hopefully', as the adverb that it is, will translate like this-- 'We will be able in a hopeful manner to pay...', or-- 'In a hopeful manner we will be able to pay...'