If you have a Hegnar, you will likely never be satisfied with any of the lesser models, even as a back up.
The porter cable is the best saw under $200, but it pales in comparison to the Dewalt at $500. I think there is a 16" Ex for $600
If you really need to have a second saw in the garage right away, and only want to spend $350. I would go with the Porter Cable or look around to see if you can find a sale/used Dewalt.
If it was me, I would go buy other tools or wood and stick to one scroll saw.