Thanks everone. some people said single is better some say there is no difference and the quad rail one has 900w of power so I think I ll get that but apart from that thanks for all the answers
I don't know how true this is today, but with some older PSUs that had multiple rails, you couldn't use connectors from different rails in a single adapter because the different rails would have slightly different voltages (one might be 12.03v and another might be 11.98v or some other such number within the ATX PSU specifications). For example, if you don't have enough PCIe connectors (not all PSUs had them when they were new), then you could use an adapter cable that was powered by a few regular 4-pin peripheral Molex connectors, but they all had to be from the same rail or else you could cause severe damage to your PCIe graphics card that the adapter is plugged into.
With single rail PSUs, this is not an issue. I know that some multi-rail PSUs were only pseudo-multi rail PSUs that didn't have this problem either. However, not only is it unlikely that your target PSU would have a problem with doing this, the chances of you doing this are slim to none, so I recommend against worrying about it. I tend to stick with single rail PSUs at this point just in case and because it's just simpler, but it's probably more of a noteworthy gimmick nowadays IMO.