SP101...ick! I can't stand these revolvers. The crane is just a bit short for speedloaders when the factory grips are installed and it tends to bind. The gun is heavy and is just large enough to not fit in my pockets. It's not small enough to hide really well. The trigger needs work. The front sight stinks and is begging for tritium. It should hold six rounds of 357 Magnum, but only manages five.
Just get a Ruger GP100 3" and be happy. Swap out the front and rear sights with Meprolight Night Sights. Get some custom grips. Buy the full kit from triggershims.com for a quick trigger job. All that's left is to chamfer the charge holes and it's ready to go. You can do all the work yourself except for the charge hole chamfers.
Or get this (treat it like a GP100 for accessories):