I will tell you how I did mine. I not sure if its the correct way but it has been working great for 30K. I used a tapped bolt that replaces one of the intake bolts. It seems really easy and you get them from various dealers (I think mine was from Geno's) I found that it was the easiest way for me to mount mine.
As for the electronic pressure sender I mounted mine (I have an 02) on a piece of grease gun hose and attached it to the engine so the unit would vibrate the same as the hose ( if the unit was attached to the firewall the hose would vibrate and IMHO break off the threaded end of sender unit) You have the 99 with the fuel ports on the top of the filter housing, IMHO you still would be better off with a piece of grease gun hose and mounting it elseware on the engine so when you shut down, etc. etc. the shake it gives off doesn't fatigue the threaded end and cause it to break in the future. Like I say I am NO expert here. I just thought I would chime in on what has worked for me.
Take Care
Mark