The Cox 049 can be a wonderful little engine but the throttle variant is rare. They can be a little finicky on fuel. There are alternative 'nitro' engines with a throttle that can be used in a powerpod on a glider of at least 72 inch span. The OS Max 10 would be my first choice.
However I still think that a motorized EP foam glider [ the bigger the better at least 48 inch span ] will give you more flying time with less hassle.