You've not really provided much information to be able to offer advice, Mark.
A rail for focus stacking needs to be better than one simply used for assisting focus. Similarly, a rail with a bridge camera perched atop doesn't need to be engineered to the same standards to that needed to support something like a Canon 1D with a moderately heavy lens hanging off the front. I've had rails ranging from a cheapy £20 offering to my current £300+ setup....and I'd still like a better one.
Bob