Lots of questions

[ConcinusMan]

What type of fish would be best to feed him?

Them... mostly big girls.

I suppose the best choices for fish would depend on your area of the country and what's available at your local grocery store.

By far the cleanest (low contaminants such as PCB's and mercury) fish I find locally would be farmed tilapia and steelhead trout. I also feed them S.F. Bay brand "Sally's silversides" from the pet store. You can't really go wrong with the silversides (arctic pond trout) but you have to be careful when it comes to fish from the supermarket, even if it's thiaminase-free.

[New Mutant]

Oh, I was talking about my snake. How big are the silversides?

[ConcinusMan]

Oh, I was talking about my snake.

LoL. I know, I was trying to make a point humorously. The point being that those two fish if you can get them would be good for your garters or mine.

How big are the silversides?

around 3 inches on average I would say. I get them from a freezer with pinkies and fish food in it, at petco.

[New Mutant]

How long should a new snake be kept in quarantine before putting him in with a current snake?

[Stefan-A]

Ideally, at least 3 months.

[New Mutant]

What about less ideally?

[Stefan-A]

Two months. There is one somewhat common disease, the name escapes me at the moment, that has an incubation period of about 60 days.

[New Mutant]

Well, I got my new boy today! He's super sweet, and I love him so much. He lets me hold him and he even let me get some nasty fleck of wood out of his mouth with my fingernail (which I keep very clean). He doesn't run away or bang his head on the side of his cage when I stick my hand in, unlike Percy. I hope that once the quarantine is over he will be a good example to Percy and teach him to be less high-strung. His name is Luke.
Here's some pictures of him and his temporary cage.