If you do indeed go with the Spider/Demon Dark Elves I agree you should use the name Drow (it's in the D20 SRD) over Dark Elves so it doesn't appear that Dark Elves are just a culture of Elves instead of a distinct faction. I'm not sure if Lolth can be used however because I believe specific named dieties were excluded from the open license (though I may be wrong.)