Lets just say its a minefield

The trouble with buying any off the shelf kit ie gaz or whatever is they all come with a 250 lb spring front and rear..
So basically if you buy a kit for a ka or you buy a kit for any escos they all come with the same spring rate..now im not Adrian newey by any means but that dont sound right to me?
I think they just think that if they can get you to belive if your cars rattling you teeth out then it must be handling great..this is not the case...