Got a tank for Christmas is it to small for Dwarfs?

Awww.....that's really cute of your wife. Congratulations! Yes, cichlids are indeed beautiful fish but as you are finding out, your current set-up is slightly too small to house a pair.

1. To prep the tank, you need to properly cycle it. You can read up on properly cycling a tank here: http://www.aquariacentral.com/forums/showthread.php?t=84598

2. The "bottom material" or choice of substrate is completely up to you and your individual preference. You could do sand, gravel, rocks, or specialized mixes like Seachem's Flourite or Eco-Complete or you could even go bare (nothing). It's completely up to you.

3. You do not need plants but they definitely add a touch of realism in my opinion. You could do plastic plants or low-maintenance live plants (such as anubias, crypts, java ferns) or you could do without. The good thing about having live plants is that they absorb nitrates (ammonia) and also provide additional oxygen for the livestock.

4. Cheapest place to buy fish on the web? Ah, that's would depend on what you were looking for and where you were located. Shipping costs can vary depending on what coast (or country if you're not in the U.S.) you live on. Aquabid.com is quite popular and our classifieds section on this site has quite a few reputable sellers.

Good luck!

I would look into doing shell dwellers from Lake Tanganyika.

I find sand not too hard to clean. All the "stuff" sits on top and it's easy to remove.
I don't know a whole lot about shell dwellers so I don't know if they dig a lot.
You could keep some plants but you may need to weigh them down if the cichlids like to redecorate.
The shell dwellers will need some shells, that's where they make their homes.
SHell dwellers seem to like a meaty diet. They would live blood worms and a good staple pellet.
For chemicals all you should need is dechlorinator. Do you happen to know your PH? Most rift lake cichlids like hard water with high PH.

Sand isnt too hard to clean although typically a siphon will suck some of the sand out. I don't know if they will dig them up but weighing them down is a good idea and while the plants do provide more oxygen, an air pump will do just as well at least. Frozen bloodworms are good with a prepared cichlid food. Yes, you will need dechlorination.

Those are sweet looking tanks...

I hear good things about shell dwellers...and the big box pet stores will not carry them... Check aquabid and online retailers for most Tangs, most LFS don't go that deep or are pretty limited..

A 6 gallon? Very small even for shell dwellers. The ONLY species I would try would be N. multifasciatus. At most you could keep a pair, however that presents a huge problem since they are not easy to sex. Size difference is generally a good way to try outside of venting (the only 100% method) and you would need to make sure you only get one male. They form colonies when given the space but when that cramped you would run into major problems with more than a pair. But then you run into breeding issues seeing as they're very prolific. You'd have to keep a close eye on fry production and removal otherwise that tank will become overstocked very quickly.

In my opinion, I wouldn't do it...but you could try.

The setup should be a thin layer of sand with the bottom pretty much covered in shells. Yes, they need the shells. They aren't picky with foods and eat just about whatever you give them. I wouldn't add any plants with this small of a setup. Not only would it just take up space but they're likely to get buried (shellies like to dig). If you have to then I would suggest a small anubias species.