My baby has over 140k miles and I am buying various parts from a member who's parting out his wrecked e36 318 1995 w 70k miles. While I'm buying few parts off him I was wondering perhaps it's a good idea to grab fuel pump (I heard they fail offten), oxygen sensor or two, air pump, water pump......any other parts that I should expect to fail on me?

My struts/arms/tie rods have been already changed so suspension is kinda fine.......any pointers are greatly welcomed :)

I don't have a e36, but I wouldn't go and buy parts just because you are expecting them to go. Some parts will last many more miles and buying something from him would be a waste. Preventative maintenance is good, but don't over do it. Just get some savings together instead and when something happens you will have it and if not then you got some cash. Good luck