I have a FM Modulator in a 04 Jeep Grand Cherokee. I recently bought some Infinity Reference Series speakers and I have a great deal of static coming through as well as a buzzing noise when pressing the gas. I want to replace the FM Modulator with a better sound quality peice. I know there is the Neo iOn adapter, but it's $190. The price is not that big of a deal but I could buy a new head unit.(alpine, pioneeer, etc.) I have read in the forum about problems scrolling through the headunits. I am not a type of person that picks each song out, I pick a genre and let it play.
So I was hoping to get some advice on what I might purchase next, better adapter or head unit. I might be getting into a sub. and amp. soon, so might a headunit be better?

Thanks for any advise or any info.