Hi MegTheFish
Transporting new fish for that length of time should not be a problem. I just received an order of fish from California and I live in New York. They should have arrived in 24 hours, but due to the recent terrorist threat against the airlines, it took them 48 hours to get here. They were packed carefully and were in good condition when they arrived.
When you buy them, ask that they be put into large bags with 1/3 water and 2/3 air space. This will insure that the water does not become polluted and there is plenty of oxygen. Sellers like I bought mine from usually fast their fish for a day before they ship them to prevent them from soiling the water too much, but since you won't be able to do that, the more water they are in, the better it will be for them.
There is another thing to consider too. When you buy fish from a source that is not local, they might be used to water that is a different pH than your tank has in it. It's very important that you slowly get them used to their new water. This part cannot be rushed.
To do this, test the water in the bags as soon as you get home and test the water of the tank you will be putting them into. If you have two test tubes, hold them next to each other to compare them. If there is any difference, you will have to very slowly add your water to theirs until they match. This can be done by dipping it out and pouring it into the bags (or better still, another container you've moved them into) at the rate of 1/4 to 1/2 cup every 15 minutes depending on the amount of water they are in, or by a drip method where a drop at a time goes into their container. Be certain to cover the container during this process because a stressed fish might jump out.
Once they are settled in their tank, don't feed them until the next day to give them a chance to rest and get settled. Keeping the lights turned off helps too. If they have had to adjust to a different pH, a tsp. of aquarium to each 5 gallons of water, just for a week or so, might help them. This is OK for corys too.
I hope you find some really nice fish!
