I would listen to different combinations before you buy. I personally chose a rotel pre/power combo over a onkyo because its to my tastes.
Goto a hifi store (a proper one) take some of your cd's or your ipod and they will demo some kit for you.
Any of the good speaker makes e.g. Mission, Kef, B&W, Ruark etc are good buys but its down to your taste tbh.
Cables, well they recommend saving 15-20% of your hifi budget for cables, I like the QED cables, i have the Silver Anniversary Bi-Wire for Front/Center's and the QED Qudos bi-wire for Surround. I also have the Chord Company Chamelian Plus Interconnects.