What DVD player do you have now (year and make, please).
I really don't think that your DVD player is going to make much of a difference if it was purchased fairly recently.
Assuming you go digital for sound and let your receiver do the decoding, you can take the audio issues out of the equation.
Next, depending on your TV and its age, DVD players these days are pretty much uniformly good at rendering progressive pictures. Assuming you don't buy a $19.99 no-name brand bargain basement player, you're going to get a good decoder that will display a nicely sharp picture. Differences start to show up as faster load time, faster speed on layer changes, other functionality features, etc. As far as basic picture goes, most models in the $100 range will perform just as well as those in the $300 range. HDMI and DVI hook-ups will likely change the above analysis, as will DVD players that upconvert. But for a basi player with component outputs and progressive scan capability, I woudl feel comfortable recommending anything from a company with a recognizable name (in electronics) for about $100.
