Rebuild or not: used BMW engine?

[xvxax]

I am going to toss this question out here despite the fact that not many of you are very familiar with BMWs.

I recently bought a stock 2.5l m50b25TU out of a 1994 325ic with 86,000 miles on it to return my car to STX, an autocross class I don't get absolutely dominated in. My hope is to run in that class next year (when not in the STi) and eventually move up to DSP or SM again long term. My donor motor was mated to a 5 speed, but it was basically driven around 2-3,000 miles a year in Florida until it was moved to PA for 4 months and totaled. The motor has probably lived a very gentle life.

Let's assume the compression is fine because the motor comes with a 15,000 mile warranty, I will verify this, but I basically want to put this motor in my car and never touch it again. What kind of things are must do while the engine is out for a car that will see about 90% track time? Oil pump nut kit, oil baffle, water pump, valve cover gasket, rear main seal, will all be done, but should I pull the head and put a head gasket and studs in it because it's so easy? Should I deck the head while it's off? Replace the weak early e36 valve retainers? Replace the crank bearings? Am I forgetting anything else obvious? Basically this build could cost anywhere from $200-1,500. I'm not sure where to draw the line because everything is so much easier with the engine on the stand. Time is basically no issue, I have until March to put the engine in. I just don't want to throw a bunch of money into this motor unless I need to. What say ye?