First of all Tuffy (and Toby) will be just fine, try not to worrey.... I know you will though
Tiki was neutered at 6 months with no problems. He was very happy to see me when I picked him up. Be sure to have a doggie car seat or someone to hold him for the trip home. He will probably sleep more and possibly eat less. Other then that just follow the vets instructions regarding licking, feeding, pain killers. He will be back to his old self in no time at all, I was amazed at how quickly Tiki was wanting to run and play, we had to work hard to keep him quiet for the first few days.
Is there anything I should send with him to the vet or have ready for him when he gets home?
A blanket, towel or maybe one of your t-shirts should be enough.
How, if at all, will his behavior change after this?
As I noted we didn't see much change in Tiki... just tired.
How long is recovery? And is there anything I need to be really careful of during his recovery?
Check with your vet, but for Tiki we just tried to keep him quiet for a few days. The day we returned home he didn't want to leave my side so I would put his little bed next to me and carry him from room to room so he wouldn't jump around... probably not necessary for him, but it made me feel better.
Hope this helps.... good luck and keep us posted on their progress
Judi