Does the Sunfire MK IV matches my system?

Could you be more especific on which models I should be looking for ?
Basically my Marantz needs an upgrade, the only reason why I got it is because I wanted hdmi for movies and it actually doesnt have a phono input for my TT.

Thanks

I am not certain that changing your subwoofer is going to do a whole lot for this setup. If you keep this woofer in check I would think it would be a fine match. If you were thinking about upgrading anything the first thing I would do is get an integrated amplifier/tuner with a better noise floor and channel separation. That is a fairly low end receiver.

Not really. You might look at something more 'musical'. Perhaps a Rel T series or something from Paradigm or B&W. Unless of course you are looking for bass quantity over quality.