You might look at Mast Mate instead. -picture.
Imo mast steps are not cosmetically appealing.
The Mast Mate uses the mainsail track and halyard to hoist, and stows away taking little space. Don't need to rem sail, just lower it.
You can use it in conjunction with a harness, and just clip to the Mast Mate while working.
I think it may even be less cost than installing steps.
The drawback is limited access to the front of the mast, which might be needed for say cleaning the contacts on the steaming light etc. However, this can be done by using a bosun chair at the same time, tied to jib or spin halyard, and just using the steps to ascend. So still can do single hand.
http://www.mastmate.com