Ah off the top off my head was some course 50mm x2 sponge on bottom, some seachem matrix and eheim bio balls, then some more sponge. Then some (purigen kinda) chemical stuff that removes tanans from water(tiny tiny little things) then some finer wool on top, not too fine as it would clog very easy and flow would drop. Tried pillow stuffing as a last layer for a while to trap all the fine stuff, but would clog way to fast. I just get a big roll of stuff and cut to shape.

Iv had no problems with the eheim so far. Touchwood, a little bit of playing around with to start with to get it set up how I wanted. Wasn't picking up alot of the smaller particals (mainly due to how I had the media in the end) swapped media around and added better filter pads ect sorted it out. Also I find the less cleaning of the filter the cleaner the water stays. After every clean takes a day or two to grab all the small particles again. Good tip is to put some rubber under the pump unit beer you screw it down. I had some bad vibration going through componts until I put a rubber mat between pump and lid. I also had trouble with the intake and spray bar over the edge of my tank cos the bracing on my tank is to large for the curve in the pipes so a little mod to the pipes sorted it out, a little annoying but workable.
All in all. It does the job it's intended on doing, which is very minimal maintenance and keeps the tank clean. I clean the filter like once every few Months, if that.