I kind of like that one for the SP101. I’m not much of a sweatpants carry guy but it looks like a good option nonetheless. I like minimalist stuff with a good functionality.You can still take your new Ruger SP101 to a gunsmith to have the hammer spur bobbed-off... generally it is a $35 to $40 job.
Also, your SP101 would fit nicely in a Fusion Holster. I have 2 Fusion Holsters (one for my Kimber K6S 3 inch, and one for my Springfield XD-S Mod.2 .45) and I really like them. The Fusion holsters feature the Ulticlip 3+, which is really nice whenever you decide to wear belt-less pants such as sweatpants or shorts. Most holsters require a belt, but the Ulticlip 3+ can be used with or without a belt. Of course you would still need to snugly tie your drawstring on sweatpants or shorts when using a Fusion holster.
Concealed Carry Holster - The Fusion Holster