If you need to save some cash, I would go looking at the junk yard.
I got a brand new power steering hose custom made for my Q45 for a lot less than $250.
The noise from the pump is probably air trapped in the system. We need to get the leak fixed first.
Once we accomplish that, you can refill the reservoir, and work the air out of the system by turning the steering from lock to lock (with the car in neutral, but the engine running).
Keep checking the fluid level, because as you work the air out, the fluid level will drop and you will have to keep topping it up.
If you really want to get a new hose, then call this group
http://www.infinitipartsusa.com/default.asp and ask for Joe.
Make sure to tell him you are a Nico member. I think you will get a better price on the hose than $250.
Good luck!