Hiya Sid.sarah,
I like the tank, and I think the stand will be okay as it is in the corner, and supported on 2 sides by the wall.
The tank will be good for quite a few years, 19 inches wide isn't ideal, but a lot better than a lot of other tanks that people keep aros in. You might be lucky and have an aro that doesn't get much beyond 24 inches, if that is the case, I would say you will be okay for a very long time, remember, as they reach 24 inches or so, the growth rate rapidly slows, so I am sure you will have him for a long time.
If people say that a 24 inch wide tank is good for life, then I am sure that your tank will be good for quite a few years, your aro will have plenty of space to swim up and down the tank, so he will be happy, of that I am sure.
Good luck with the tank and stand, and I hope the aro enjoys it.
I have had my silver for about 6 months now, he was about 8 inches long when I got him, and now he is about 16 inches long, and starting to get some real depth on his body.
All the best, and don't listen to all the comments, as I think your tank will be good for quite a few years.
Mike.