Logos already has Yusuf Ali's translation of the Quran. I assume that is for purely apologetic and research purposes. But that being the case, it also seems necessary to have another good translation, in light of the theological issues surrounding Islam and their view of the Koran.
A.J. Arberry's translation is one of the best, although the versification is different than Ali's that won't be a problem in Logos. In fact, it would make things much easier since anyone who has more than one Quran knows how difficult it is to find the parallel passages by flipping back and forth in hard copies.