new gmt800 owner, please help me sort some stuff out

[Stephen717]

So I recently came into possession of a 1999 Silverado z71 with a 5.3 while visiting friends and family over thanksgiving break from the school work I'm doing for my new job and it didn't have a key, replaced the lock cylinder (after removing the steering wheel to get the old one out), cut the two wires in the column for the passlock system thinking that was the reason it wasn't staying running because the previous owner showed that it ran fine (when hotwired which is what made me think they messed up the passlock system to begin with) when I was working on getting it on a trailer to bring back south. While I was crawling around under the truck I found the abs module needs replaced and I found a clogged fuel filter, replaced the filter, truck runs great, idles around 500 rpm. so I guess my questions are should I get an abs module from pick and pull and try it or reroute the brake lines to a tee and a union to bypass the abs system all together? and should I get a new matched ignition and lock cylinder set so everything works off one key and hook the passlock system back up or should I just leave it disabled and call a locksmith to get a key made for the doors? I was also looking at getting a new key fob since I didn't get one with the truck and was wondering if it would work without the passlock system being hooked up.

any insight to these problems would be greatly appreciated as I've never owned a vehicle this new. pics of the truck will be up shortly