One ceiling light in an assumed large family room, that is being used as an office? Supplemental desk lights. If not an office (just relating you want 50fc rather than 20fc?) and just want general brighter light, then supplemental floor and table lamps. A brighter single central fixture will just allow glare and you'll have shadows anyway since you won't be directly under it. A multiple stem fixture will probably not extend to the areas you'd prefer it.