Oh, as for types of fish:
Black Mollies
Sword tails
Angle fish
Guppy
Orange Tail Shark ( I don't recall their names)
Get a Pleco to help keep things clean.
Aquariums are a lot of fun if you get into them. I've had several and my most favorite was my Discus tank. Discus being the type of fish, but they are harder to keep alive. I also had a Salt tank, but like was said, a ton of work plus you don't reap the benefits of a pretty tank for a long time. It's a living organism and the pretty colors of the corral have to grow.
Stick with that first list to start. it'll determine if he really enjoys aquariums. How many gallons is it. You'll want to keep the amount of fish proportional to the size of the tank. 1" of fish per gallon of water is the typical ratio, depending on filtration. i.e. 10 gallon tank, you can have two 5" long fish. or ten 1" long fish. A good filter is an important part of the system. if you want more fish, get a bigger filter. but start him out with what you have and see how he does with it.
Plants, fake are good. One less living thing to care for, but do this, they have dried bulbs and plant food. Get some and plant them as per instructions and see what happens. I never had that much luck with the live plants, but I grew some huge plants from the bulbs. They are also a means of filtration.