I recommend the site Mentorcity.com. It connects with your LinkedIn profile and you set up more details describing your soft skills and professional expertise, the things you are looking for and the things you have to offer. Then up to four recommendations come up for you to consider as a mentor, you set up a 15 minute conversation to see if you want to work together and you go from there. The site has very useful forms and resources, references and ways to connect. You can very specifically target the skills and type of support you are looking for in a mentor and there is less likelihood of the "chemistry" not working. Give them a try and let me know what you think! Oh, did I mention it is free?