You might want to check out
http://www.u-bowling.com.sg for good bargains. I suggest you get a polyester ball package (should cost around 140-160 maybe, lost touch with the current price) since you will be getting used to the fingertip ball. It is ok to continue throwing from right and make sure u get the pocket consistently. Do that for about a year, then switch to reactive ball. You might want to do a bit of research in google on the difference between polyester balls and reactive balls. From then onwards, your ball will defintely hook more than u expect. Morale of the story - Slowly progress from house ball to polyester, then to reactive (mid perf ball) and lastly reactive (high perf ball). Try not to rush to a reactive ball immediately as it may affect your basics.
Btw, dont worry about changing too many balls as next time you might be able to use your polyester ball as your spare ball. Cos when u switch to reactive ball next time, lane conditions will affect how your ball moves down the lane. At that time, polyester ball will be useful for spares as it will not react to the lanes as much.