Hi Digger, both Risen and Longi are very similar in terms of quality and performance so it really comes downs to the installer you choose. The local installers are almost always the best option as they generally will be contactable and more reliable than traveling or interstate installers/contractors from other companies.
Also you will want to look at the installer (not salesman) that has invested the most time and bothered to visit your home and check your roof, switchboard and ideal location to mount the inverter with you.