Yep, thats the go. Bit by bit and get the best quality stuff (in your opinion) you can fit in your budget. Make a cd of your favorite tracks and go audition some splits. Pick the ones that sound best to you. Look for brands such as focal, boston acoustics, mb quart, hertz, morel, DLS... etc. Do a search for other brands as well.
Jaycar kevlar splits are ok for the money (~$160) if money is tight. I have also heard that JVC make some $200 splits that are very good for the money. Some of the specialist brands above also have entry level stuff around $250. Expect to pay ~$500 for good quality mid range splits though. $800 to over $1k for excellent ones. Try to find stuff on special. Alpine have some very good value pakages at the moment. Maybe you might like the sound of their speakers, personally i don't. Although the type x are ok. I prefer the focal sound, others don't.
Remember to budget for sound deadening the front doors at least. Good speakers deserve good installation, they will give their best then. Made a very noticable difference to the mid bass from my focals. Well worth the time and money.
Have fun, cheers.