Given the revolution in ammunition performance sparked by the FBI ammo tests, any of the JHP products of the major manufacturers will do very well for your purposes. Every 'stopping power failure' I've ever been able to research has been a failure to hit vital areas of the body.

What you need to bear in mind is that the ammo must: be reliable in YOUR weapon and magzines, shoot to the point of aim of YOUR sights (or get your sights adjusted), that YOU can fire accurately and rapidly (where necessary), be readily available and within your budget. Do not be overly impressed by the number of plus signs in the designation for your ammo type, driving a modern bullet beyond it's design envelope can cause failures due to lack of penetration.

Generally, the closer the profile of the bullet is to a ball (FMJ) round, the better it will feed. As an example, regular Remington JHP ammo will feed in anything that will feed ball. You can practice with any ball ammo that reliably feeds and shoots to your sights.

The last time I was in Wallyworld, they had Federal Classic 9BP for $17 for 50.