Avoid Sony, a brand who's reputation was made 30 years ago and was mostly destroyed in the last 10. It's not that reliable.
Aiwa and Technics are reliable and perform well, and Aiwa tends to have better than average FM tuners in their receivers. A decent receiver without Pro Logic sound costs less than $150, and the the quality of the CD player is irrelevant because quality equipment never has a built-in CD player or tape deck anyway. Matsushita (Technics, Panasonic) CD players seem to be the most reliable (and for portables, the longest play time per set of batteries).
There's not really a lot of difference in quality except in speakers, and don't be fooled by in-store performance because results are affected by volume (louder speakers are wrongly perceived to be better), floor position (corner floor gives most base, middle of wall away from corners the least), and bad bass (worse bass is perceived as better). Consumer Reports has good speaker evaluations, contrary to what some people think.
Some amplifiers aren't rated to drive 4-ohm speakers even though such speakers are actually fairly common, so you may want to check the specifications. Amplifiers are supposed to be designed to shut down when overloaded, but many aren't and are expensive to fix because the whole amp section may be contained in just two large chips.