We had dragons for a long time when my Son was 5yo. They were awesome pets! Now we only have 2 Leopard Geckos, and 5 running aquariums. I will try to get some pics of Spots and Banana Man.
As for your ro/di search, I have had AWESOME DEALINGS with Jim at: http://thefilterguys.biz/
I had to replace all 3 of my prefilters, and I went ahead and got a new membrane too, and it was much cheaper then anywhere else I could find. Jim was very helpful when I called him too! They sure know their stuff!!!
I know it is a big cost upfront, but you will NOT REGRET IT!!! It is very comforting to know EXACTLY what is in your water!!! And if you plan on going to expensive shrimp you will want to know what they are living in! With a few small tanks it won't add too much to the water bill compared to gas and other expenses for going to the grocery store! I would also recommend you getting a TDS meter when you get your RO unit. They are only $30 or so, and are easy to use!
I am wanting to take the shrimp plunge soon too! I just have to come up with the cash and other stuff I need to get my tanks I already have going like I want them!
I really like the wood placement in pic #1! It draws your eye from back to front and left to right as well! I bet your shrimp will LOVE climbing all around it too!!!
Have fun and be safe with your new tank!!!