At this stage, a battleforce is perfect.
You get your 4 destroyers (how many I have in a 2000pt list), another 20 warriors (giving you 44- just under what you can fit into a 1000pt legion), and 5 scarabs (giving you 11, and more than enough for a full unit).
Other than that, a foot lord would be a good idea- convert the Warscythe you get with it into a SoL.
Alternatively, if you havn't built your DLord yet, then you can use the DLord's SoL arms on the foot Lord to give him a dynamic pose and a SoL, then have the DLord either as a warscythe wielder (a Dlord with a 'scythe is a lot more useful than a foot lord with one or just as a normal destroyer- you get all of the parts).
I would recommend the latter- I really don't like warscythes, no matter what Feb's WD says.
That would give you, with the BF and Lord:
1 Lord
44 Warriors
5 destroyers
11 scarabs
That's well over 1000pts.
Get a monolith then, and you've got your 1500 list- and a very strong one.