Being adopted myself, my personal thought is that if God is leading you to adopt on your own and you'll have a strong support network of other family and friends behind you, by all means, please consider it.
I've known two other adult adoptees (both girls... if that makes a difference, I'm not sure) who were raised by single mothers and no father present, and they stated that they never felt a loss or as if something were missing--they were happy having just a Mom. One was an only child and the other was raised along with four sisters, whom her mother adopted as well.
I agree with you wholeheartedly that the love of one parent is better than none at all. Although I have two wonderful, loving, Christian parents, I've been back to my orphanage and while I know the staff there is extremely dedicated, a care institution just can't compete with having a family--and God puts together families in very special ways, sometimes with just one parent. I had thought of adopting as a single as well at one time... I don't believe it's where God is leading me but I've had the privilege of working on a team to help another couple adopt.
I wish you all the best in your endeavor.