Harmonic Balancer/Pulley/Timing belt questions

[FirstSVX]

The pulleys on my car were making noise. Then one day the pulley AC bearing siezed. I decided to look at power stearing bearing and it felt rough. Then I noticed my Harmonic balancer was loose. Further examination and the key (Crank to Harmonic balancer) was broken.

I have seen part numbers on the pully bearings but I can't find the thread now.

I have been waiting for the funds to replace the timing belt and water pump because I do not know the service history of the car. Currently the car has 150000 miles.

How important is it to replace all the pulleys when doing a timing belt replacement? Are the ebay kits any good? I would rather have a Subaru water pump.

Sorry I am so wordy...Thanks for the help.