My answer to you is to go with your heart. If you want a Grey, then please get one. As long as you closely supervise Mushu and your new grey companion, it should work out fine. Greys CAN get along with cats and many end up being able to manipulate the dogs and cats of the family. Many end up being friends with the cats. But the most important thing is to be sure to supervise their interactions. Also, let Mushu KNOW that no matter what, your Grey is family and should never be "messed with." Animals are smart and they know not to do something when their humans communicate it to them. Keep them separated when you are not present... at least until you know and are sure they will get along.
Many Grey pet humans work for a living... and they work away from home. An eight hour day away from home should not be a problem, as long as you can let your grey companion out for about 3 hours at night when you are home. They do need a lot of attention, but you can still have a life. If you are away in the day and night, that would be a problem. But as long as you are able to give attention at night... most nights, it should work. You also have the weekends.
So again, Kris, if it is your heart's wish to live with one of the most fantastic creatures on Earth, then go for it! Let me know what happens.
PS: Thanks for the compliment on the website!