Okay.. I'll have a go at this,
I'm doing similar with a 5', 370L tank.
You're looking at the following:
Protein Skimmer (I went a Deltec MCE600)
Powerheads (2xSeio M820's in my case)
Salifert Test Kits (reading has told me there's no other) - Ammonia, Nitrite, Nitrate, and some others if you want to keep corals.
Rock, either Base or Live - an indication I've seen from reading is 0.5kg/gallon, but I'm sure that's debatable as well. This is what provides your filtration/converts ammonia all the way to nitrogen gas (even past the nitrate stage us freshwater people are used to) so is very important. Definitely reading enough to understand the differences between Base rock, Live Rock, and Cured Live Rock
Sand/Argonite Stone for the bottom of the tank unless the bare bottom look is your kinda thing. There's also the option to go DSB (deep sand bed) which would need a heap more sand.. I suggest reading a heap before making this decision.
Lighting - if you want to keep SPS corals you're going to need some serious lighting, think around 300W (very rough guess - others can do better than that I'm sure), T5 or Metal Halide lighting is your best bet to get that much light in a small space.
If you want to run a sump, you're looking at another tank (to be the sump), PVC plumbing, and a return pump. The advantages of a sump are that you increase the total volume of water in the system, making it more stable, and also gives you somewhere to hide the skimmer/heater/dead bodies/etc/etc. There are more advantages I'm sure, but someone else better than I can answer that.
Oh, your heater will work fine as long as it's not stainless steel.
The aqua one cannister filter is pretty much useless, although I've read on reefcentral.com (sign up there if you haven't.. awesome reading) that some people are using the larger ones (like the model you have) as a refrigium. Not sure on the milage there, but using it as a normal filter will just generate nitrates off the scale which you don't want.
And the main thing you need, is patience... truckloads of it.. forget all the timeframes you learned in freshwater... they don't apply