How about a 2006 jeep grand Cherokee do I need a deq test for it?

Yes

Now I read I can pick up DMV tags here to... apologies for all the questions I've never had to do this for my car before.... now can I pay for both my DMV tags as well as the deq test tags all in one trip?

All 1975 and newer cars, trucks, vans, motor homes and buses powered by gasoline, alternative fuels (such as propane) or hybrids registered within the Portland testing boundaries. All vehicles new to Oregon will need to be tested.