Officially you should fully pronounce both of them with even a little aspiration between. However, many speakers actually don't aspirate it and instead cut the first fricative with the stop needed for the second plosive. Whatever you do, don't just make one "ch" sound and don't just hold the fricative portion a little longer.
DuraS ghawran je most straightforwardly means "Duras and Gowron", in that order.
"Gowron and Duras" would be a better translation of ghawran DuraS je.
If you are experimenting with alternative word orders to test the flexibility of Duolingo, please don't -- I'm sure we've got enough real errors left that can take up our time sorting through the reports without wasting (as I see it) our time going through reports that merely suggest non-default word orders or ways to say something.