Its the new Sun Power cells, which can ONLY be bought with a PV powered inverter. SO no chance you will do the "wrong" thing and thats why Sun Power won't sell just panels
The Suntie will smoke if you revese the input for a postive-ground system. Only a special PV-Powered unit (or a PV series Xantrex unit , 50kw+) will work with these panels
For the Suntie, ANY Si panel except the Sun Power that you can actually buy will work, since its low-voltage, just add 48V nominal strings and your good to go.
For the best price check out
http://www.ecobusinesslinks.com/solar_panels.htm