Hey Geoff,
My first tank was the same as yours, the elite 60 right? and I'm guessing you got it from pets at home cos thats where i got mine lol.
Yes I would recommend live plants in your tank and the other thing I would recommend but prob not until your tank has finished cycling because you'd knock it further back, would be to replace your filter, that 'stingray' filter supplied with the tank is pants and I replaced it with a fluval 3 and found the upkeep of the tank much easier.
I went from the elite 60 to the elite 95 and now I have a jewul rio 125, if you are planning on getting a bigger tank at some stage, go for the biggest one you can afford and house as you will find the bigger tanks are easier to maintain a good water quality.
Andy
P.S Sorry also forgot to mention, I got my marimo balls (moss balls) from ebay from this seller: epetz-direct
I got 5 for £6.50 with free delivery and all 5 are just smaller than tennis balls so a good size!
Also if you are looking to replaced that little 'pot plant' with a live plant, then use the terracotta pot (if the fake plant comes out of it) and lay the pot on its side in the tank, digging it slightly under your substrate, they provide a good little place where your fish can go hide or lay in and they look quite good in the tank.
Andy