Take the antimalarials it's just not worth the risk, malaria is not be be messed with. You're in the privileged sitution of being able to afford the drugs so take advantage of that. I've taken dox before I had vomiting and mouth ulcers. However I had but no food poisoning unlike my malarone taking friends! Some people find that when they get back home it becomes difficult to keep remembering to take the tablets for a month and they don't complete the course. My current prefernce is malarone (or malanil in Kenya) as only needs one week after and one day before so handy for spur of the moment trips up country. I've had no side-effects.
If you are travelling through Nairobi, or any major town, then most pharmacies will stock it at around Ksh180 a tablet, which a believe is cheaper than in europe so you can pick it up here. If you can afford to go to lamu and on safari then you can have your pick of drugs - as alsacienne above says 'Bite the bullet. Pay up'.