Well, you will need ground-bound models to represent the scouts should the
LSS be shot down or you disembark. There are two ways of doing this.
You can go the route of buying a Scout Squad for each
LSS and making sure you have enough to go around. Most expensive, least effort.
You could, with a bit of work, convert the
LSS scouts to foot scouts, base them, and just leave the
LSS empty. I can't see anyone having an issue with this rules wise, and it's the cheapest way, although more involved.
You could go the whole hog and magnetise said scouts at the feet, so you can have them on the base or the
LSS, but this is going to need a lot of work to look right.
For reference, here's a Scout using the reposed legs and body of an
LSS rider.
Hope that helps.