Separate beds are in fact halachically required for when the wife is in niddah. There are ways to disguise two beds so that they seem to be one bed. Furthermore, a couple can actually have one large bed and use a trundle bed or mattress for one spouse during niddah.
It can take a while at first to become accustomed to different facets of niddah observance, including separate beds. If you are particularly concerned about your ability to observe this halacha, we invite you to share specific concerns with us so that we can help.