Jim makes excellent points.
I would add, and re-enforce:
Big fish should only have big tanks. and you should always research your purchase BEFORE you go to the store. If you see a fish you like, ask the store to hold it for you, most will. Go home, research it (some fish stores will let you go through their books right there!) make sure you have the right environment for it, know the difficulty, and make sure you are up to the task.
Case in point, Arrowanas, the silver can grow to astounding proportions, I have seen one 4 feet long in an 800 gallon tank... THe other consideration for an arrowana is water quality. It must be spectacular, or the arrowana will suffer from a condition known as gill curl, and infact, if you see this in your tank on an arrow, it is a sure sign it's way past time for a water change. It is easily reversible, but constant poor conditions will cause permenant damage. (I have heard of people doing home'brew surgery on it... but...... you get the idea... a gallon of prevention...)
By all means start out with a 10 gallon tank. It will teach you stringent husbandry, keeping up with water changes, so on, so forth, but as soon as you feel you have learned your lessons I would move up to the biggest you can afford and house. Why? Simple, larger tanks are larger eco-systems, and tend to fluctuate less. Above all, when you get a larger tank, avoid the urge to overstock it! Let your fish have their breathing room!
I think the Eclipse tanks are great starter tanks, but if you buy all the parts seperately, I would reccomend an Emperor power filter. Skip the undergravel filter, it's not out-dated as some people say, but I do believe better things (like the bio-wheel on an emperor) have come along, and it will be detrimental if you want to keep plants. The emperor will be enough. As with carnivorous plants, pack as much light over them as you can (if your growing plants) if you control your feeding, change water, and don't over-stock, you shouldn't have algae problems.
We are always glad to help and talk about our hobby here, so ask away!
BTW, as some have said before, many times the most gratifying tank you will ever keep will be your first one, with the 'simple' fish many people move on from to 'greater' fish. If you find something you love, like a sword, or a rosey barb, enjoy it, stay with it... and remember, if 6 months down the line you like your rosey barbs, but want something new, RESEARCH! Make sure your tank is not stocked to the limit, and that the new fish/what not, is compatible. That leaf fish may look cool, but when you see a rosey barb shaped lump in his tummy... you will drop your jaw in awe at how wide that suckers mouth can get!