Definitely agree on the water entering the sump at the same end as it leaves the display tank. Your set up there looks like it would be very noisy.
Traditionally a sump would have the filter components right at the start of the sump tank. There are a variety of reasons for this, one of the big ones is that water entering the sump with be more oxygenated so aerobic filter bacteria will have better conditions. There's nothing wrong with the way you've done it though.
As said, you're probably looking at needing more flow than you've got shown there, but to be fair, the filter you have is capable of running like that, but could probably do with being more powerful. I have a sump that runs my volume up to around 400 litres and my pump is rated to 3100lph, but then I like good flow.