I am a member of CA. We have a very small district and there are very few sober women fit to sponsor. I had to look outside my fellowship into AA for my sponsor, and it has made all the difference.
Congrats on being willing to start your 4th. I would suggest that you find a sponsor immediately upon starting this step because you will dig up alot of old resentments. I needed someone to talk to while I was doing mine because once I started writing the tears started flowing. It was hard for me to remember everything I had done (harms) and everything I thought was done to me.
Prayer is absolutely imperative through this process. "Made a searching and fearless moral inventory of ourselves" The opposite of fear is FAITH!!
In my experience, I cannot complete a 4th step until my sponsor checks my thinking on it (my part in it, and defines resentments)
In our district, we like to say (and no offense meant by this at all!) "If you are sponsoring yourself, your sponsor is a moron"
Also, its not the quantity of time, it is the quality of sobriety that matters. If someone only has 2 years, but has been through all 12 steps successfully, I wouldn't pay too much attention to the amount of time, but rather to what they can offer to you.