I agree with jsaras, you should have a good room with good monitors, but i add cables aswell.

he has a one stop store for all you need at a cheap price.Don't restrict yourself to one plugin,The more options you have the more you can sculpt your masters with precision,and have less limitations and more uniqueness from track to track. You don't want every track sounding like it was done with Ozone.I use Voxengo's aswell,Soniformer multi band compresser (delivers a high end well balanced mix sound), Harmonieq (true to your audio adding no coloration),Voxiformer for voice (the best on the net), analog flux (for old school analog sound),elephant limiter etc. You want A plugin like izotope Ozone aswell because it adds unmatchable pro quality gloss and shine to your music, aswell as give you a multiband compressor and other effects that are better than the plugins that come with most editing prograams, certainly more sophisticated.Izotope ozone will clear your mix up when it is clowdy.I use Izotope Ozone, Cd Architect and many other Mastering plugins, The key is to have a variety of mastering plugins if you can afford it, This will enable your tracks to have different flavors. Your going to want a separate wave editing program and plugins.You want a wave editing program like wavelab, or the cheaper cd architect so you can do your Red book DOA burning, Album crossfades,hidden tracks, PQ coding, ISRC coding etc.

Wavelab mastering software