That's a great cage for the time in between juvie and monster

You would need something larger in the end--and the space is not the scarey part, neither is the really big pool or the GREAT filtration system---to me, the food bill is.
Anyone who tells you they feed a healthy monitor of that size crap from the supermarket and not *mostly* whole prey, they do not or will not have a healthy animal themselves after a while.
They need big whole prey---and unless you plan on breeding and prekilling (feeding live will make them more agressive---along with all the parasitic reasons we do not do this) you will need stock in
RodentPro

But hey I know what you see when you look at them...I LOVE waters. All big lizards are really nice animals. If you can afford it and have the room---and realize the commitment----go for it.
Just don't be a putz and not post pictures if you do