Hi James,
What age car have you bought as I believe there are 3 different versions? Early, I believe it was updated with DBW throttle so 95 or 02+

I had the chirrping problem after my car was sat for a while when repainted. I followed Kaz's procedure to flush the solenoids which initially solved the problem but I had a pump failure shortly afterwards.
I found that a CRX assembly is the same and managed to buy a compete ABS unit for £25. The only thing I found different was the plug on the end of the wire so just swapped with the original unit and all was good.

Hope that helps

Olly