mk2 front coilover spring rate.

5kg or 280lb 

I put 225lbs in when i put in my grp4 struts as i was worried about going too stiff, after getting them in i could have gone heavier but am happy otherwise.

Assuming you already have the rears, find out what rate they are and determine what you want from the car, oversteer, understeer, lift off over steer etc. Then to take the guess work out look up an online spring calculator and go from there.
Cheers Drew
 

Back in the days some 15 to 25yrs ago the thing to do was to Capri strut your mk2 Escort to give an extra 1.5in travel to the bump stop . As for bottoming out, it never happened on mine and I drove it hard n fast and occasionally flew up to 3ft off the ground (Salisbury readers will know the road) . I'm not saying my setup is what to go for but was very predictable at speed and was simple, the ride was not soft or harsh . Rear was Bilstein and an extra main leaf added but the baby leaf removed, tramp bars and LSD , front was Capri struts (gusseted) using Cortina mk2 roller tops with koni (later went Gaz) with v6 springs cut to my desired height and a 24mm adj sway bar . The car was fun and easy to slide but also great on fast corners . The setup was somewhere between rally and tarmac . Still have the car but not driven since 2007 !
I've prolly given no help here but it really depends on what you want , track car, fast road etc , it's a case of try it and see till your happy.