Or you could use svg2mod. This way you can put your design on any layer. (The inkscape layer name defines the kicad layer.)
You can also say that by using inkscape to create your design you have a nice user interface build in already.
Here my attempt using inkscape and svg2mod: (I used 10x10mm for the overall size, this way you should be able to easily scale it to whatever size you need.)
I used the path difference tool to get the isolation gab. (The isolation gab is designed with a simple path. This path has a stroke with set to an appropriate value. When happy with the settings simply convert the stroke to a path and subtract it form a circle.
The svg file: (rightclick to download as svg.)
The kicad mod file with circular pads (type connector):
my_attempt_with_pads.kicad_mod (49.9 KB)
I used precision (-p) = 0.25, this gives good results but if you scale it smaller you could increase the value.
python svg2mod.py -i [absolute path]/my_attempt.svg -o [absolute path]/my_attempt --format pretty -p 0.25
If you want to use it i would suggest you download the svg, open it in inkscape and scale it to your final dimensions.
Set the isolation path width to your desired value, convert it with stroke to path. Create a new circle on the Cu layer and remove the artwork from the circle with path->difference.
To get a circle on cu ou can simply copy the circle from the mask layer and move it to the cu layer. But you need to remove the stroke. This way the stroke width of the circle on the mask layer defines the mask clearance. But remember that half of the stroke is inside the filled area.