Do you have access to a welder and get a 4 ft long, 10" wide and 2" thick solid wood block? Width can be 12" if you want to meet IPF standard. I can privately share the drawings of a very cheap but sturdy bench that you can easily make or get made. I hope Rip doesn't mind the design IPR infringement, if any.
Here is what I made:
YouTube
I used 50x50x4 millimetre box channel for frame, 60x60x6 mm L angle for base, 8 mm thick plates for gussets. The frame is powder coated black (I like raw steel, but I live in a coastal town where corrosion is a serious issue). The bench is 430 millimetres (17") tall. Wood is of "Kadachi" tree (no idea what it is called in English, but you may use any furniture worthy wood). I gave it a clear varnish coat with matte finish even though it looks a bit glossy in the video because the paint is still drying. Total cost was about INR 5000/- (US $67).