The one thing that I am finding challenging about aquaponics is that all the good stuff for it seems to be sold in the UK or AU. There seems to be little that I can find in the US, hence everything has to be hodge-podged together. I do understand there is a system MFG of a high quality system that is a contributor here, but getting into the "thousands" category is beyond my means (although I am sure they are worth the price.)
Here's the mistake in your thinking about Aquaponics....it's a DIY (Do It Yourself) technology. There are companies that sell ready made setups, however unless you are blessed with endless cash, it's time to reach down deep and pull out that pioneer spirit and start figuring out how to DIY (Do It Yourself).

The very object of Aquaponics is to get away from store bought and produce your own whether it be the Aquaponics setup or the fish and veggies that are produced through Aquaponics Technology. Break out that Coonskin cap and start thinking.

3. How can I filter out all the fish poo, but yet same it for my other plants?
Your plants do not need or use the poo....the poo needs to be filtered out and broken down by nitrification bacteria to create nitrates (nutrients). That's what the plants take out of the water.

As for removing the poo from your tank, you can use a number of ways and the simplest and least expensive if you have a large buildup over a period of time is to manually siphon it out. However, as long as the water chemistry is in balance and the water is remaining clear even with the accumulation, then leave it until it is just absloutely necessary to remove it because of the bulk of it. Whether the poo is filtered out or laying on the bottom of the tank, the bacteria will still do their job.