Re: Wht to buy??
oh, thought you were in pakistan, accoring to your skin condition, your skills in makeup and the makeup you are not going to use again, i suggested you get your makeup done from a parlour.
Anyway, if your budget is good, try dior, thier liquid foundations and very natural and the powder is very fine that it gives a natural glow rather than caky look.
If you are on a tight budget, then try thick liquid foundations without any powder, i never had good experience with primer myself, so won;t recommend it. try using oil absorbing papers after applying liquid foundation, i have done that when i had very bad skin a few years ago, and it worked for me, hope it works for you too.
Also to be on the safer side, do try to do makeup using different techniques mentioned above and below to practice and find out the best technique/makeup that suits your skin.