Hi Bowman - welcome aboard.
While I tow with a Grand and not a chero sport I did nonetheless have exactly the same issues you described.
There is debate in here about using:
1. airbags in rear springs - downside is airlines can be a nuisance and can get ripped out when off road.
2. stiffened/progressive rate springs - rear of vehicle is jacked up further when unladen but on some vehicles I've had this was not such a problem.
I wanted to maintain standard suspension so went for Hayman Reece ride levelling hitch from ARB - see
http://210.10.49.162/gallery/Hayman-Reece-Hitch
My laden trailer weight is 1900kg. The hitch was fitted and set-up by ARB so that the rig sits dead level. When not towing, I simply slip the tow bar and hitch with swaybars off and store, thus leaving vehicle dead standard. Theoretically there is an added advantage that the sway bars assist with stability when underway.
I must admit that it is hardly noticeable on the Grand but could be noticeable with your vehicle. The assembly is heavy at ~13kgs and this may or may not be an issue for you. Cost was abt $590 odd fitted I think.
I hope this helps until a chero sport owner comes along.
ciao