i would say wood is easier to level, its pretty hard to make a metal stand. my dad does have welding equipment since he repairs old cars and other machines. but you cant really just start metal working that easily, you need special blades to cut it, your gonna want to have a sander as you need to sand down the welds. i would be pretty worried that i dont weld the stand right and the weight of the tank would cause it to bend. i would want to have more expierence metal working before i put hundreds of dollars and pounds of water on a stand i made my first go. personally unless your good at it i think it would look like crap.
also theres a rusting issue, stainless steel would last along time but will eventually rust. if theres salt involved in your tank i would skip the metal definitely.
btw if find your stand has termites, i would be very worried not just about the tank but about your house, i would contact a exterminator asap