Have kids, want pet with physical contact

Question
We just sold 2 parakeets, have 3 fish and a snail.  Kids are 5 year old girl and 2 year old boy.  Girl wants a pet she can hold.  A cat or dog is not an option.  Have read in a magazine white mice are good choice.  Went to Petland, was directed toward Black Bear hamsters (though did not buy anything because employee lied multiple times while there - so we left - with my daughter in tears).  I know as a child I had hamsters that bit and were not friendly to hold.  Also, they lived to try to escape, it seems.  Do not want that.  I understand no guarantees.  The physical interaction will be supervised by an adult.  I want to be sure of what I am doing before I buy something.  Pets are for keeps, and I want my kids to learn responsibility in keeping their pets.

What do you recommend (since this is hamster forum, I am not asking about mice, though if someone knows, appreciate all help I can get)?

Would two hamsters be better than one, for companionship?

What sex do you recommend?

What cage do you recommend?  Seems Crittertrail has very mixed reviews.  I read one of your posts with a link to an aquarium setup.  Could not see what lid configuration/material was.  

Any other advice is needed and welcome.  Not sure what all questions I should be asking.  

Answer
Well let me start by addressing hamster friendlyness. SOME hamsters are nippy, but the majority of hams are pretty laid back, and I've never had one bite me who wasn't ill. When choosing one, don't pick based on color, but spend some time around the hamster tank and handle as many as you can. The one that feels best to you, the least squirmy, and healthy is the one you should pick. If the store gets ansy trying to sell you a hamster then walk out, you have the right to handle each any every one to find the kindest.

There is no real difference between owning a male and a female hamster. Try to get a male from the pet store straight off because alot of times if you buy a female she runs risk of being pregnant. Male hams will have a large, protruding bottom by a certain age. If you can't tell, then they are too young to be a good pet. Alot of people will tell you to buy a young one, but in my experience the young ones are very jumpy and squirmy, the old ones (3-6 months) are far less squirmy, and much larger and easier to handle.

Syrian hamsters can't be kept together, syrians are the big, normal sized hamsters. They are only together in the pet store because they are usually of the same family, and are young enough to tolerate one another. When they age they will get territorial towards another ham, and will fight if kept together. Dwarf hamsters are gerbil sized, and can be kept in pairs, but they aren't great for beginners, especially if you want to handle them, they are very jumpy.

Aquarium cage 100%! aquariums are large, roomy, and can have many add ons. Those plastic crittertrail cages are a nightmare to clean, way too small, poorly ventilated, and hamsters love to chew, and they will simply chew on that plastic cage, which gets VERY irritating. Also bar cages are not much better. They are drafty, and the hamsters will chew on the bars because they are stationary. The picture to my cage setup is:

http://i21.photobucket.com/albums/b275/Hezadancer/Pets/6-28-06008.jpg

I wouldn't recomend my setup though, my hamster sleeps, eats, and uses the restroom in his lookout tower, making it very stinky. If you stick to an open aquarium, 10 gallons and up, the hamster will have plenty of room, and are easily cleaned out.

Yes, hamsters love to try and escape, but with an aquarium they have little chance of escaping. The only time mine ever have is when I had a metal water bottle holder, and they would climb up it to get out, my bottle now is smooth and he cannot climb out. The current one has only escaped once because I forgot to click the lid to his look out tower in place. As long as they have nothing to reach the lid in your tank, they can't leave.

Overall I've had lots of pets, but if you child can handle a parakeet fine, then a hamster is a piece of cake. I have owned a parakeet and did not like it at all compaired to as much as I love my hamsters. Just handle many and pick the perfect sweetheart to take home.