Those are the same things.
If you do not want to financially support pfSense, you can buy hardware from Netgate directly, starting from $299. Even cheaper as a kit or with older hardware, but you decide for yourself whether it will be adequate for you. I'm planning on buying an assembled APU from Netgate for myself; right now I'm using m0n0wall on a separate P3 PC (Celeron 1000), modded for silence. Probably will try out pfSense beforehand, on a separate CF card I just ordered.
The Netgate APU2/APU4 devices don't appear to be available directly from pfsense. They do say money from them goes to pfsense though (and they advertise them on the pfsense site)
Reading the forums there are some dual LAN Atom based mini PCs that seem OK.
Edit: Also http://store.netgate.com/Desktop-Systems-C83.aspx has some preconfigured options at under $300.