I chose to do the grad nurse thing right after graduation (only in Ohio, it's called a "grad tech"). But I graduated this past Nov, became a grad nurse then, and passed boards in Dec.
If you know you're going to be studying for boards for a little while, then I would go ahead and work as a GN. If you feel like you're ready for boards, but can't decide to do the GN role or just go in as a RN, I would just take boards and go in as a RN. You're going to get oriented to the unit and all of that either way. I, personally, chose the GN route so that I could be earning enough money for rent while I was waiting to take NCLEX.
Good luck to ya in whichever way you decide