Legacy RS

Hi

I've recently acquired a set of Tanabe Sustec Pro coilovers for my legacy ('89)as the standard suspension was worn out. They're from an imported Impreza and as I was told, sure enough they fitted straight on. The problem with them is that the springs are ridiculously hard and even these 'posh' struts aren't able to damp the non stop bouncing they cause on our crappy local roads!

I've checked the inserts and they appear to be tip top, so I need to get softer springs as I've been told by loads of people that Jap import cars often have silly hard springs on them, the likes of 500-700lbs!!! Problem here is that I've no idea what the standard rates are for Legacy springs let alone for slightly uprated ones.
The guy at Leda said it should be 350front/250rear for an upgrade, but I wanted to check if any of you guys can clarify what sort of rates I should be thinking about to make sure I don't buy the wrong ones as it's bad enough having to get rid of the ones I've got!

Any clues would be much appreciated!