A couple of mod questions for my '07....

So, i'm on the way to mid traveling my 07, since long travel is so ridiculously priced and not practical for my current lifestyle. Seeing as this is my current situation, i have a few questions, and would be grateful for as many different opinions/suggestions i can get....

QUESTION #1: Suspension...... I have formulated a theory and wonder if it is practical and will work the way i intend. Camburg UCA's and their upgraded race spindle has been stated to be a functional mid-travel set up for the front. I have heard everything from 9'' of usable travel to 10.5"... I already have the coils, so I'd like something to maximize my travel potential in the front...
For the rear i have been informed the defined engineering shackle under axle conversion is the way to go... they boast a 15" claim... is this fact? and would a mix of that front and rear be a solid mid travel build??

QUESTION #2: Engine Mods (including CAI's) ...... URD is the most promising kit i have seen to date. looks like a true CAI and boasts a pretty big power increase... is this a solid purchase? im not looking to burn cash here...
Headers... Is it even worth the money? or am i gonna give myself more of a hassle than a benefit by buying a set of headers? will i see any improvement?

QUESTION #3: Cutting my rear fenders and building a new rear bumper ...... I have not seen a single 2nd gen tacoma with angled rear fenders and a single bar rear bumper... why is this????? i think it looks AWESOME on other trucks. have people tried it on 2nd gens and been unhappy with the results??? or am i just a pioneer??

QUESTION #4: HID kits ........ i have gone through 3 sets of HID kits. for some reason one headlight or ballast always goes to hell...... is there a kit out there worth purchasing??? im tired of doing this over and over... i would like to get a one and done kit... question pt. 2: are projector kits worth the money, and will they truely improve the dispacement of light pollution??? or are they just meant to look cool???

any answers/suggestions/help would be greatly appreciated....
Thanks Guys!!!
-a curious taco owner out of Orange County...