Hi there! My soon to be 4 yo loves digging in the sand at the park so DH and I were thinking we wanted to get a sandbox for him for his birthday next month. Does anyone have a suggestion for a good one? I know that we need to have a cover for it but that's about all I have. The ones that I see out there seem too small given that we our boys are 6.5 and 4. Though we don't want this huge monster sized sandbox!