Why would any gun be enough?
Even a rifle with multiple 30 round magazines is of little to no use if your entire plan can be summarized as "rely on my gun"
Is there a way you can make your home's exterior less visually desirable?
Can you deny your attackers easy entry into your home?
Is there a system in place to rouse you from sleep and alert neighbors and/or police?
Have you determined a place in your home that gives you a realistic advantage?
Have you developed a plan that gives you a realistic advantage?
Have you sought out training that would give you a realistic advantage?
Home invaders have a few issues facing them
1) The invaded home needs to be worth their risk / effort
2) The homeowner is a bit of a wild card
3) The homeowner can impose a severe time limit by calling 911
Make the exterior of your home highlight the risk and downplay the reward of breaking in.
Put the bad guys on the clock. Then be an inconsiderate jerk and run down the clock by making getting in really hard.
Prepare yourself far beyond buying a gun and then spending many internet hours trying to find the perfect ammo; Prepare yourself by strengthening your plan, your home, and your mind, body, and spirit. The gun is the least important bit.
Oh, and .357 is way too big of a bullet. If I only have 8 shots before reloading, I wouldn't want something with such a gargantuan diameter. If I only get eight shots, I want my bullets no bigger than .30 and held in an en-bloc clip.