Is there an alternative to malarone (atovaquone and proguanil) / other anti-malaria tablets?

Yes. If taking prophylactic anti-malarials is not possible then the best way to avoid getting malaria is to use insect repellents on your skin which contain deet, insect repellants on your clothing which contain permethirn, sleep under a bed net and avoid being outside at dusk when the mosquitoes which transmit malaria are most likely to bite.