I would also lose the casters on the bottom. Unless they are appliance duty and secured real good I would get rid of them. If one gives out after you got that tank in there, could be disaterous.
But all in all I think it would make a great looking stand.
125 Gal-35 Gal Wet/Dry-Tetra-Tec PF500 HOB
(3) AuquaClear 301 Powerheads-600 GPH
Automatic Tempature Controller
5-6 Inch Sand Bed-200+ lbs of LR