Power Steering replacement

I have a 97 GMC Savana van, 5.7 L. It has well over 200K miles on it, and we try to keep it up like new. This past 8 months we have drained savings to do so, with A/C, front end and other major repairs. We do love the car, and it does not use a drop of oil, tranny is good (rebuilt about 3 years ago). Anyway, after spending all this money, the power steering pump started making noises turning right and left, upon startup. After 5 minutes the noise ceased. One repair facility said it was the small check valves inside, and they were sticking, so they use some secret PS fluid that had teflon in it, and after a week or so, the noise stopped, then about a month later started again, although it still goes away after 5 mins of startup. We decided to go ahead and replace the pump, but we (I) decided to do it myself. :(
Now the van is torn apart, and I bought a replacement pump, at which time I found out that this vehicle has an EVO system, (electronic variable orifice) which appears to be a solenoid type setup at the high pressure hose connection. No parts houses in town stocks the pump/resevoir/EVO setup, only the pump and resevoir. I am not prone to cheap it, and re-install the old EVO valve, as it might be the culprit making the noise. Any feedback/reinforcment of this decision would be appreciated. My option is to wait 3-4 days for one to be shipped in from Kansas City.