20's will fit just fine, go with a 20 x 8.5" rim with somewhere around a mid to low 40's offset and be sure to run a 245/35/20 and you will be ok.
As for kits, do a seach, theres an andys autosports kiy, a viper kit, and a showcars kit,
There is also an alternative to going with a kit, you could install an ES/R/T front bemper which would give you factory fogs.
not much in the performance section, but you could go with a K&n setup or a joeKD intake for a few horses, As well as a more free-flowing exhaust.
As Isaid run a quick seach for these thing and you'll be sure to find all you need.