Well,
If you like Hifonics...its a good company...just need to know which models are good these days. So I'd recommend the Hifonics Gen XI for starters.....
If you wanna spend more money....then you have a few choices...
Zapco C2K , PPI , Diamond Audio D7 series, Avionixx, Phoienix Gold Ti series
And for the sub.... I think the Inifinty is way overpriced for its performance. Im gonna go ahead and recommend a pretty popular woofer around these forums that I had apleasure of hearing this week. Its the Elemental Design A series of woofers.
These are one of the best sounding subs I've heard.... And seeing the flatcone move is austonishing to say the leest.
Im not some bass head recommending kickers to you or anything...but these reproduce very hard...accurate...and deep bass.
Another woofer that comes to mind is either a Diamond audio M6.... or TDX and Eclipse has nice aluminum subs and the Titanium line is for that extra umff //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif
AS for the headunit..... The alpine 9815 is good unit. Unless you want an Eclipse or a Nak.....then that alpine should keep you very happy.