If those two adults together weight only 218 lb, then that useful load will work, but I think you mean a payload of 450 lb, and that may not be within the reach of any of the AA-1x's. Typical full-fuel payload is under 400 lb, even on most AA-1C's, and full fuel is only 22 gallons (132 lb) to start with. AA-1C's typically weight near 1100 lb empty, and with a 1600 lb MGW, that leaves not much more than 500 lb useful load, and that translates to less than 400 lb payload with full fuel. I think you folks would either need to go on a serious diet or learn to travel with a lot less baggage to make an AA-1x work.
Doc's suggestion of an AA-5/5A Traveler/Cheetah makes a lot of sense for your plans, particularly if you're traveling any distance, because range on the 2-seaters is pretty limited unless you don't mind landing with nothing but fumes in your tanks. We owned an AA-1B for four years, and never planned more than 2.5 VFR or 2.0 IFR to have adequate reserves for my comfort level (60 minutes fuel in the tanks on landing) -- typical fuel burn is more like 6 gph in cruise. Yes, you can throttle back to 5 gph to extend range, but folks don't by a speedy plane in order to go slow.
You can extend AA-1x range with the 10 gallon aux tanks, but there is no MGW increase with those, so they take a 60 lb bite out of your payload, and that pretty much limits you to either solo flying or no baggage at all.