This is a discussion on Aquarium advice for X-mas present within the Beginner Freshwater Aquarium forums, part of the Freshwater Fish and Aquariums category; -->
Instead of airstones I would reccommend a powerhead with air intake for aeration/ circulation, but you probaly don't NEED it, just a good filter ...
Instead of airstones I would reccommend a powerhead with air intake for aeration/ circulation, but you probaly don't NEED it, just a good filter (aquaclear 50-70) is enough. And yeh... the canister filter is probaly a good idea if you use sand.
I have ecocomplete in one tank and like it but it is $$$. I have sand also in multiple tanks and my plants do just as well there.
On the Aqueon heater... I have a dozen or so of the Aqueon Pro heaters from 100W-300W have had zero problems.
HOBs are inexpensive, but overrated as a long-term biological filter (since the HOB media is typically replaced and has less overall surface area than most canister setups). I use both types of filters on some tanks, canister only on others, but would never rely solely on a HOB for my primary biofiltration. The HOBs are great for pulling larger chunks of crud out of the water quickly.
Lastly, water circulation, not the air bubbles is the critical issue for oxygenation - as long as the canister outflow is disturbing the surface a little, you are fine on oxygenation!