Hi and welcome SoapShy!!! I'm fairly new to soap making myself, but I will try and help you!! Ok, I did a little research, and here is a lnk that I found, and they offer organic melt and pour base.
www.soapbasics.co.uk When you use the word natural, are you trying to say animal and cruelty free? Because then I think instead of natural, you can use the word vegan. Don't quote me on that, but this website appears to use organic (certified) melt and pour that is gree of sls and environmentally friendly. I believe SLS is a harsh surfactant that a lot of people try to stay away from. Another one is Soaposh, at
www.soaposh.co.uk/store/Default.asp and they also feature organic bases and clam to have exclusive soaps just for their company. Check them out and good luck!!