Any gun small and light enough isn't going to be "enough" to reliably take down a bear.
It's going to be a compromise no matter how you look at it. A powerfully revolver is going to be very heavy. A tiny easy to carry 642 is just a pee shooter in terms of bear defense.m Your going to be somewhere in between. And shorter barrels don't let you get the most of the caliber. It's a compromise any way you slice it!
I never liked carrying the SP101. Mine was a 3" 5 shots. I thought it would be the holy grail but it wasn't. I sold it.
I also tried the G30 thinking it would be the holy grail, sold it too. I still recommend it thought. If it fits your hand well then I think it's worth a try. Rent one and try it before you buy. I think it's a love it or hate it proposition!
I feel most comfortable carrying my CZ Phantom. Its the right size, grip texture, capacity, shootability under stress, and the weight is the maximum I'm willing to carry. I have a hip holster and a shoulder holster for it so depending if I'm wearing a pack or a jacket etc, I'll choose a carry method that works for the situation. I've accept that it's a last ditch caliber in terms of large animal defense but that is also very low on my list of "worries". If I didn't have this gun I'd probably carry something like a G19, CZ PCR, USPS Compact, SR9, etc. I also shoot this gun often which helps with confidence in using it under stress.