Depends on your standards. On my system, I just changed it to "index.php"
I just make sure all my main pages are named that way, even if they don't have any php code in it (they work anyway).
If you need both, I think you can specify both seperated by comma and it will look for the first and then the second if the first isn't found; but you will have to check the manual on that one...
-- Rich --