If you only have one pump how are you going to transfer your sparge water from the keggle to the cooler with it while you are recirculating the mash at the same time?
Call me cheap but I went with 3 525pc and have no issues with them and at 1/2 the cost of the 525ss it left my money for another 10 gallon batch of brew.
Ritebrew.com has 525pc for 18.49 and 525ss for 32.99
I just converted my 50' 3/8" IC into a 50' CFC and it works great. Why use both a CFC and pre chiller when you can make life simpler with a larger CFC?
They are much cheaper at www.spraysmarter.com
131.94+ shipping
I ordered my 15 gal conical from them and shipping was under $20 and it got here in just a couple days.
I used my new sq14 for the first time last weekend and it had no problem boiling 14 gallons with the regulator below full blast.
It also supported the weight of a very full keggle with no issues.