Hi Erica86 and welcome to our little beginners subforum!
I was thinking about your query up there and about this thread and I realized a lot depends on your experience. People come in to our freshwater beginner section with all sorts of very different experience, which makes it hard sometimes to know whether one is giving the best advice or the right comments for the query. In my own case I had the weird combo of having many prior years of basements full of fish tanks, some breeding and a lot of reading and trying, but in fact I had been away from the hobby too many years and was really a beginner again when it came to many of the modern things of the hobby that are very helpful and core to the hobby.
All that's just to say that if you happen to be inexperienced in the hobby in general then we might advise caution on a number types of tanks and approaches that you are discussing. Discus tanks, tanks with some of the more rare species and certainly the entire marine hobby could all fall under the heading of "Advanced" or at least "Intermediate." Of course, terms like that are usually generalizations and one can't rule out the really ambitious beginner who truly has the energy and means to go directly in to the more difficult things. But -usually- the caution is well-founded in that its very, very easy to get discouraged in this hobby if you get yourself in to the more difficult fishkeeping situations too early and grow frustrated when the results turn sour. Just plain community freshwater fishkeeping takes a whale of patience and work. Intermediate and advanced problems can go way beyond that!
On the other hand, if you allow yourself to press forward for about 2 years (I find this a good learning period) purposely practicing the keeping of what would be considered a relatively easy freshwater setup, then what happens is that you can have some very happy success and be kind of subconciously absorbing a set of basic skills in the hobby. Then, when you branch out, you'll find you can recover better from setbacks or problems that occur more often from the more advanced attempts.
We have some great stocking members who frequent here and I'll bet they can dig up some rather nice and unusual freshwater fish (perhaps some dwarf cichlids of various types?) that are both unusual but would also qualify for getting through those first couple of years. Then if you were still really strong on the hobby, you'd be set with the skills to branch out even more.
Now you'll probably tell me I got it all wrong
and you've been at it for quite some years! Not to mention that it sounds all preachy or something. Yuck!
~~waterdrop~~