I started off by ordering HPS Premium bags/struts. I've purchased the majority of my stuff from Kevin at ACC. He is local to me and has been extremely helpful
5 gallon aluminum tank: $100
SMC water trap: $39
110/145 PSI pressure switch: $19
7 switch rocker box: $90
Viair 400c compressor: $189. After discussion with Kevin, I went with the 400c opposed to the 480c that seem highly popular here. The 400c has faster fill time, 30% cycle (if I remember correctly) vs. 100%. Apparently is known to have less issues and appeared to fit my intended use.
Air line worked out to about $40. I'm running 3/8" to the front bags (even though the HPS bags come prepped with 1/4" NPT to 1/4" PTC fittings) and 1/4" to the rears.
Kevin tossed some leads in for my front bags for free
PTC fittings cost about $5-6 a piece. I'm using PTC fitting from the valves to the bags and between the tank and the water trap. All other fittings I managed to find elsewhere, I'll get to that later.
Tire valve: $4. A great back-up in case the compressor fails. It will allow me to fill up the air tank using a conventional air pump at a gas station, etc.