I think Hogue makes a Bantam grip now, too. I use their regular wood ones on my SP101 and it fits in my pocket. Herrett's offer a Detective grip and Badger makes a grip for them.. Might also check Ahrends and Craig Spegal as they make abbreviated wood grips. I don't know if Ahrends makes Ruger grips; others say Craig Spegal (Bay City, OR) makes grips for Rugers.
If you have a minimum of tools the SP can be disassembled to put the springs in. The mainspring is the bear but can be done with a little thought. If you put a new mainspring in I would go with at least the 10 pound one to avoid misfires.
Here are some websites:
Badger:
http://www.gunaccessories.com/Badger/index.asp
Hogue:
http://www.getgrip.com/
Herrett's:
http://www.herrettstocks.com/album.htm
I think you will really like your SP.
Jim T.