Mouse choices depend on what you want to do. Mostly, you do not need to get a specific mouse. You should get a budget mouse if you are planning to play casually.

Most PVP and most mini-games are in 1.8. This is why a good mouse must be chosen. For 1.8, a decent CPS is required at least above 10. It is recommended to learn a clicking method, usually butterfly or drag-clicking. For butterfly clicking, many mice will work, but the Glorious Model O is the best. For butterfly clicking, it is recommended to take a mouse that can double-click. For drag-clicking, it is recommended to use the Bloody A70 or the ROCCAT Kane Pro. These mice can get over 50 CPS for drag-clicking. 

Butterfly-clicking is better for consistency and PVP, but drag-clicking is required for extra CPS. For god and telly bridging, drag-clicking is required.

For 1.8 PVP, aim is required as much as CPS. If butterfly clicking spoils your aim, learn how to do both. Specific grips help a lot.

This usually does not need CPS, but it is still good to have it. For bridging, drag-click is recommended. For this reason, cheaper mouses like the Glorious Model O is recommended. Despite this, any mouse will work, and bridging can be done by and mouse.

Most clutches need high CPS. Budget mice will work, but drag-click will help. Any double click or drag click on the mouse will do. However drag clicking is more of a high risk/high reward. If you're not good at drag clicking and mess up, so do the speedruns. And 50cps is not required in speedruns. The Glorious Model O or even any mouse with a wide surface area for the left click is suitable as long as it doesn't block your CPS.