Law of supply and demand at its best.

If you plan on keeping the boiler I would do the hydro air as @Rick Bassett mentioned with the air handler in the attic if possible to supply the heat and A/C. 

As far as San Francisco (and New York, LA, and Miami) goes, I just would like to add housing is always supply vs. demand, of course, but it historically it is correlated with jobs and medium household incomes.

I think you'll find are stronger cash flows in some parts of Durham and many areas of Durham are transitioning so the appreciation looks to be very strong. 

The BEST option would be to replace it ALL as well as any metal supply piping cause its time. 

@Derrick Craig,I'm feeling the same way that you are about the market being stronger around here.  

It's a nice gesture to supply a fire extinguisher under the kitchen sink or maybe one in the garage for safety, right?

To keep the hard cost down somewhat I DO plan on doing some Serious negotiating as far as supplies and labor goes .Not that I am a cheapola but there are bargains around if you shop hard enough .

If I am in a partnership where my partner owns and supplies the house and I supply the renovation budget.

Yes, it's possible to make some money here but the market is super hot, a lot of investors here have extremely deep pockets and the demand is out stripping supply by a wide margin.