Having an s14 myself, thats a big tyre to learn on, you would be better off going for a pair of 225 40 18's, they will probably be slightly cheaper too but with a similar circumference. As mentioned above start with high pressure to make it easy to get the back end out then drop the pressure. On your first day you will probably spend a fair amount of time spinning so tyre brand and pressures aren't going to be as noticeable as say a couple years into drift days.
Good luck and have fun!