I want to try a build (for fun, not practical use) with maximum Spirit regen—what items and skills should I equip? What is the maximum possible rate of Spirit regeneration once all of these perks are in use?
The Fist of Az'Turrasq(fist weapon) can roll up to 2.33 Spirit Per Second.
That puts us at 6.66 per second from gear.
The Chain of Resonance Passive gives 2 per second whil a mantra is active.
The Mantra of Healing with the Circular Breathing Rune gives you 3 per second.
So as far as I can tell, the max maximum spirit regen, disregarding Spirit Generator skills is 11.66 points per second.
Now, the listed monk fists attack 1.40 times per second. With the 15% dual wield bonus this you can attack 1.61 times per second. So 6 spirit per attack from Spirit Generators gives you 9.66 per second assuming you are attacking as fast as possible. This does not include any +% attack speed you may have, but I'm not sure how to find the max you could have on gear with the Spirit Regen Items.
The Breath of Heaven skill with Infused With Light rune will double this amount to 19.32 spirit per second.
So with this build, you are guaranteed a maximum of 30.98 spirit per second.
Please note that some skill runes will increase the spirit gained from an attack when you crit, so realistically if you have this exact build you will be able to average more per second depending on your crit chance.
Other items to consider: