OK, I'm going to take a wild guess that its a b13 se-r, in which case you would want to get the master cylinder from another b13 se-r or nx2000, then you want to get the passenger front brake line, that could come from any b13 sentra or nx as llong as its a non abs model.
On my car I was able to get away with routing the rear lines directly to the mastercylinder and didnt even need to use the fluid block. The abs unit is a distribution block, while the non abs one is more of just an extension block, and my car works great without it.
I believe you also need the driver side brake line but I forget, it would be a good idea to grab it, an get the whole line, the metal an the rubber part that way you have backups of the soft line.
Also its nice to have a brake line cutter and flare tool, I bought one years ago and have used it several times.
I went as far as pulling the carpet up in the passenger floor board an taking the plastic kick panel off to get the abs computer out, the wiring is tangled up pretty good an it took me hours but i got it all out lol..
this post should be of help
http://www.sr20-forum.com/608187-post584.html
heres the abs wiring crap i took out
http://www.sr20-forum.com/608983-post590.html
The rest is up to you man.