You might want to check out:
http://www.roydeanacademy.com/
Roy holds dan ranks in Aikido and BJJ, plus he posts here occasionally. So it is definitely possible to do both arts (I do as well, so do many others on AIkiweb). Roy also publishes the excellent Electronic Journal of Jiu-Jitsu (EJJ) which focuses on a wide range of topics, including the mixing of Aikido and BJJ.