Personally, I would tell you they will be fine. Professionally - No mater what the distance, I always have a TSU (Transportation life support unit) rigged before any transfers take place. Now most of the time, I am moving sharks etc., so obviously this is more important with them, than with those of the smaller stature. However, this may seem unecessary to you seeing as smaller fish are shipped in bags all the time. This is true - but do I prefer it, or accept that as the best way - NO. Honestly - yes you would be fine for a couple of hours as long as the water temp was regulated, they were kept in a cool dark place (as to reduce shock), and there was a hearty amount of oxygen sealed in the bag to start. With smaller fish, I will typically have a few blacked out 5 gallon buckets, some air-stones, and small powerheads attatched to each bucket, powered by a portable generator (you can get these at Home Depot or Lowes). I am really picky when it comes to transporting anything, so you may be cracking up at how narotic I must appear. Either way I will tell you that yes, you will be ok, as long as you use common sense, and basic preparations for the move. Plus it's not going to be only 3-4 hours before they get to your tank, because you will need to transfer them to a holding area with the water they are transported in, and then slowly acclimate them to your tank paramiters (which you need to have perfect before you even pick them up!). All in all, you will be looking at a minimum of 6-7 hours start to finish, if done carefully and correctly.
so that should work i figure