I have been running my diy trickle/tower filter on my 55gal cichlid tank for almost a year now and it has worked amazingly well for me.
I have a cpr aquatic cs90 overflow, I tried making my own but I am very satisfied with the ~$100 spent on the cs90. Connected to the nipple on the overflow I have a Tom Aquatics Aqualifter AW-20 to remove air that builds up in the cs90 and to restart the siphon should the power go out and somehow the siphon fills with air/breaks. The output line of the aqualifter is directed into the back of the cs90 (in the narrow section that should always have water in it).
The overflow empties via a section of pool filter hose to my tower. I built my tower by taking 12 and 6 quart square clear poly-carbonate food storage containers that I drilled a grid of drain holes in and stacking them with various filter media in each bin. Mostly I use green scotch-brite scrubbies. All of this is supported by a small stand made of larger diameter pvc
inside a 10 gallon tank located under my 55. I have most of the 10 gal
tank filled with more green scrubbies and then at the opposite end are the two return pumps that feed back into the 55.
Hope this helps you figure out yours.