Im looking to get my brother some new speakers for his murcury. He is mostly into rap music and therfore would probably prefer something with bass over sound quality. His current speakers get pretty muddy at high volume levels and I know that bugs him, so some sound quality is important. He has a panasonic deck (50W x 4) and no subwoofer. Please give recommendations for brands and models, since at this point I am not sure the size of the speakers. My budget is about $200 for 4 speakers. Thanks guys
Based on that, go with a set of 6x9's in the back for the added bass he's looking for (since he won't be getting a sub). To stay within your budget, go with 6.5" coaxials in the front.
This recommendation is based on what you said in your original post: no sub, bass is more important than pure sound quality.
Now if you're willing to spend a bit more, the ideal setup is a set of 6.5" components in the front and a sub. A small 8" is all that would be needed for your purposes. Consider if you can spend anymore than $200. If so, this second option might become possible.
If I can be of any further assistance, feel free to PM me. I'm happy to help out.