For slow flying speeds and that soft landing at that size the loading should be no more than 9 oz/sq foot. 7 to 8 would be better. It's that old scaling factor or Reynolds number thing at work again. A 6 oz loading for a 2 meter glider is feather float territory but for a 25 inch span model it's getting close to the heavy sport model region. For your lower wingspan limit I'd say 6 to 8 oz/sq ft is best but for the 34 inch span you can get away with up to 9 to 10 quite well. It COULD fly with up to 11 or 12 but then the landing speed would be higher.

A 34 inch wing with a 7 inch chord would give you 34 x 7 = 238 sq inches which is 238 / 144 = 1.65 sq feet. 1.65 sq ft x 9 oz/sq ft = 15'ish oz. I know from my other models that such a model would have nice low speed charactaristics. Not a floater by any means but it'll have a nice easy to handle glide speed.