If you have the finances available to purchase an iPad outright then purchase the iPad that way you have no commitment to the network. Afrihost Mobile prepaid is the way to go or alternatively you can purchase the SIM card that comes preloaded with 200 MEG data per month x 12 once-off cost R49 Telkom Mobile or RedBull Mobile
If you a heavy user. You can always load R1800 airtime(if finances allow) convert that airtime to 120 gig(if you're covered by Telkom Mobile only network). Then you can use the tether option on your iPad and share internet connection with your notebook.
How much bandwidth do you consume a month roughly +/-