disco sills

i have a disco 1 i am very slowly doing up.
the sills are quite rotton under neath the plastic trim, the question is can i put rock sliders on the disco instead of new sills or do they have to have sills and the sliders.

do you know which sills have gone, i had to replace both sills on both sides. there is an inner and outer,
the inner is like a rectangle box that bolts to the out-riggers and the outer sill provides the floor and outer edge of the sill.

Was a slight bitch of a job to do, but got it done for £300.

Sorry but as for the Sliders im not really sure.

Stu

replace the sills with (i think) 60*40mm Box section - acts as sills and rock sliders.