A pillar Gauges

Exactly, the braided line for the fuel pressure will be a b#tch to get routed under the stock trim!!! I have my fuel pressure in a guage bezel dual mount along w/ my boost, and have my A/F ratio along w/ my oil pressure on my dual pod. The autometer bezel isn't the highest quality though - so maybe you could consider mounting your fuel pressure on your cowl outside old school style. Not great for a daily driver, but looks sweet for a weekend cruiser!!!
 
Correct. I have the electrical guage. The only thing I don't really like about my fuel guage (and this is true on any 99+ returnless fuel system) is that the needle bounces around. So when I'm at idle for example, the needle bounces between 31 and 34 psi....I know it's at 32 but it jumps a little.
 
Well, the electric should be used anytime inside a car for fuel pressure. its less accurate, but much safer. a fixed mount mechanical gauge can be mounted under the hood for tuning, and referencing against ur elec unit, but i would only mount elec inside. just my 2 cents