You can have two back up guns, neither will do you much good if you can't bring it to bear in time to help yourself. You can use whatever you want, as someone who carried a gun daily as part of my job and still does I am simply recommending you go to another kind of holsters, there are many to choose from that give you good and quick access.
I doubt any holster would hold the two different guns you specified. An ankle holster has to be tight as it moves, especially if you are in a foot race.
A knife rides better there. A friend that loves ankle holster got me one once, wore it a week and then it got permanently retired. Can't cross your legs, and your pants will ride up on it if it is really on your ankles.
If the SP101 is your backup piece, can I ask what your primary carry is??
i disagree with you. i carry a smith and wesson model 642 on my ankle in a Desantis ankle holster while i am on duty. i can remove my backup very fast. its all in how you train. it is a very effective way to conceal a pistol if you are wearing loose pants at the ankle. if you were rolling around on the ground with someone it is very easy to access you weapon. again i feel a weapon concealed on the ankle is a very good place to carry.
cisco, look at the Desantis ankle holsters. very well made and very comfortable. i cary on my ankle everytime i hit the road on duty. practice different scenarios. it is very fast to access your backup as long as you have loose pants around you ankles. with practice you will draw as fast from you ankle as any other concealed holster area. trust me i feel i could draw my ankle gun faster than most people could draw from an in the pants holster