Sump pumps are not designed to pump pressure. What you are doing by using the smaller discharge is creating excess back pressure on the pump and basically reducing its effeciency and the life of the pump. If you are wise enough to invest in a Zoeller, Do yourself a favor, and upgrade the discharge to handle the performance of that pump.
With that being said, I chose not to go with the above in my home. The previous owner installed a sump pit, and garden hose discharge attatched to a generic pump. Pump failed when I used it to pump water out of the forms for my driveway (oops). I replaced the pump with another small big box special, because my sump only saw water this spring for the first time in 5 years. It ran 1 time every 1/2 hour for about 3 weeks, then the sump is dry again. I saw no reason to put a pile of 20's into the hole for something that gets used very very little. If I had a situation where there was water constantly, I would go with the zoeller, and the 1.5 pipe.