That's not a factory GPS unit. They look a LOT different than that item.
Was a new thread really needed? Everyone was helpful in the last one. It's clutter like this that isn't needed in the forums and makes it harder for new guys like yourself to find answers to questions that have been asked many times.
As for your questions. That is not a factory head unit. This is
http://www.ebay.com/itm/2009-2008-2...t=Car_Audio_Video&vxp=mtr&hash=item1e6a99e985
And if your okay with an aftermarket company, like the one you posted, get it from a reputable brand such as these.
If you want to use your current dash and just get a dash kit you could get a single din unit like this.
http://www.ebay.com/itm/Kenwood-KVT...051?pt=LH_DefaultDomain_0&hash=item20c2532bb3
Or you could get this
http://www.ebay.com/itm/DODGE-RAM-G...Parts_Accessories&vxp=mtr&hash=item4cfe50393c
Then a head unit like this
http://www.ebay.com/itm/AVN726E-ECL...9180b&item=120743073803&pt=LH_DefaultDomain_0
or this
http://www.ebay.com/itm/KENWOOD-EXC...0819163157?pt=GPS_Devices&hash=item4162206015
Of course these are just ideas.
Victor