Hello and welcome leopard tortoise freak. You gotten nothing but great advice so far. Sounds like you've got everything worked out. The more space they have the better, but upgrade the tank size as he gets bigger. They grow a vastly different rates, so there is no way to know how long that tank will last you, but probably a few months at the least. Maybe as long as a year, if you have a slow grower.
Have you planned your outdoor enclosure yet? Direct sunshine is really important for them for as much f the year as the weather in your area will allow. Exercise and natural grazing outdoors is also very beneficial.