Decided on the Pennzoil fluid transfer pump because it is ruggeder than the Heinz, the handle can be screwed down to shorten the pump to minimal size for storage, and weighs only 0.6 oz. more than the Heinz.
Obtained a Sawyer "PointOne" filter unit, and it works OK with the Pennzoil fluid transfer pump. The set up was juryrigged, and so was leaky, but with some care could be easily tightened up, reducing the weight of tubing to a minimum, and increasing the flow rate. The flow is not quite so fast with the filter attached, but still faster and easier to pump than a Sweetwater, and at least as fast as a Katadyn (Pur) Hiker.
But the weight - there's the rub. Unfortunately, the many who tout the weight of the PointOne filter at around 2 1/2 ounces, neglect to state whether that is wet or dry. When in use while trekking, the weight will be wet. I found that the wet unit with all excess water blown out of it came in at over 3 1/2 ounces, making it substantially heavier than the pump. Without blowing out the excess water, the weight was up around 4 ounces.
My best estimate is 3 1/2 to 4 ounces, plus the pump, prefilter, and hoses will bring the weight up to at least 8 ounces or more, and that's not counting a WP carry bag with compartment to keep the parts separate, a syringe or squeeze bag said to be needed to backflush the PointOne once a week or so, and misc. repair parts.
The Sweetwater Walk-A-Bout is around 12 ounces and 14 ounces in a sturdy bag with cleaning brush and float. But I've found it to be totally reliable and clogging has never been a problem. Just brush it out, rinse, and it's ready to go. Eventually, the cartridge has to be replaced, but I've never had to. After a number of years, I did so just to be on the safe side. The Katadyn (Pur)Hiker pumps easier and faster, and weighs a couple more ounces. I've not used one for any length of time, so don't know about clogging issues with it.
With all the failure-related issues I've read about on this and other sites about the PointOne, this project doesn't seem worth pursuing at this point. Will stick with the Sweetwater until the industry comes out with something at least as reliable, and significantly lighter. Sorry this thread has not ended well. But that's all folks.