OP: I think you answered your own question. If you want to be a bedside RN in the future, then you may want to choose a job by bedside now. Unfortunately, no one will be able to tell you what your future holds if you take this job now or you take a bedside position because many of us have found that no matter what work experience we have, the demand for our skills in the future depends on the local market. In other words, if you have work experience in one area of nursing, you will essentially be stuck/trapped in that area if the market is tight and is only interested in nurses with experience in X. On the other hand, if you live in an area where employers are desperate for anyone with a license in nursing to accept a position outside his/her area of work experience, you may find that there is more flexibility to move around in your career.
By the way, I think it is very cool that a new grad has an opportunity to go straight into research nursing. However, from my experience many RNs who become research RNs are those who already have experience with direct patient care and the critical thinking and solid soft business skills that comes from years worth of bedside work experience. Thus, I think even in a good research residency program, you might find it to be a bit of a challenge compared to your more experienced colleagues.
In any case, good luck! I am making moves at this time to further my leadership career in research nursing so I am a bit bias in favor of this specialty at this time.