a usb mobile modem, you get it everywhere here. and do take your ipad with you, there are many cafes etc offering wlan.
mtn and the others are offering sim cards as well which you can then cut according to the ipad size. it is all less complicated here, you get a sim card, put the apn in and there you go, you are online.
there are a number of places dealing with "european" or "white" hai so no worries.
don't sweat it with the fear of aids. the thumb rule is be careful at the hospitals when giving blood for malaria or other tests and be sure to protect yourself if you are gonna shag. ghanaian men hate condoms, hence the rate keeps rising.
if you need help, just gimme a shout.