Alpine makes some of the best quality headunits out there, in my opinion. I always recommend MB Quart speakers because theyre amazingly clear at all levels, but if you plan to go without a bass set-up then I would suggest JL Audio or Kicker speakers inside for a little more fullness at the low end. Also keep in mind that Alpine has some small 4channel amps that plug directly between the headnits harness with no wiring needed. Itll boost your RMS wattage to 45 per cjannel or so.
If you just want brighter headlights, why not just upgrade to PIAA bulbs? If HIDs are what you want then youre already on the right track.
In regards to suspension, I say take your time researching rims and drop heights you like, then decide which one youre more deadset on. I personally picked a comfortable ride height first because that matters more to me. You may end up being deadset on a set of 16" rims which would need a little less drop than 15"s. It all comes down to your preference in rim size.
By the way, you seem to be on top of your research which is great. Not enough new members do so. I like pointing it out to those that do. Youre definitely an a good educated direction. Congrats on the manual EX. I look forward to your progress.
