I agree it is to late for this batch, but it is a good idea to get one for down the road. There are lots of choices, and going for the cheapest on is not always a good thing. Many of the cheaper ones run on old wafer technology to control heat. They are very touchy, and the heating element inside is usually gets very hot and poses and hand burning risk. Then you also have fan or no fan options. Fancy ones even offer humidity control at a much greater cost. If you buy one you really have to dig into your pocket book.
Brinsea makes good ones, but they get expensive when you add an egg cradle to turn the eggs. You should look at the Octagon series
http://www.brinsea.com/products/octagon20A.html
They are on sale right now, due to getting into winter. The lowest model without the cradle runs right now at 99 dollars. The better one with cradle around 380 dollars. I do not own this one, but there are many that like it. I own a GQF incubator. I did my research and found this one to be the best for the money. The one I choose runs on 12 volts internally making it very save. It does have a plug for 110 with a little inverter to bring it down to 12 volts for the machine. You can run this machine on a 12 volt battery, in the case of a long power outage or in you car's cigarette lighter. Newer bothered with the battery because it is well insulated and handle an outage of 8 hours, if you wrap a towel around it.
http://www.gqfmfg.com/store/comersus_listItems.asp?idCategory=30&orderBy=sku
I have the genesis 1588 for 129 dollars. There is nothing you need to adjust, just plug in and you are rolling. It has a Styrofoam body, which holds the heat very well, and you can buy a replacement if it breaks or gets to dirty. I had tons of hatches and it still looks like new. For duck eggs you can get a goose egg turner so the eggs will lay on the side, or you turn them by hand. I went out all the way and got the one that comes as a complete kit with quail eggs, and quail and chicken egg turner.
http://www.gqfmfg.com/store/comersus_viewItem.asp?idProduct=66
You can add the goose rails to it and you are set for all kind of eggs.
http://www.gqfmfg.com/store/comersus_viewItem.asp?idProduct=97
Don't forget to get the vitamin additives to get the young ones going off to a good start
https://www.gqfmfg.com/store/comersus_viewItem.asp?idProduct=231
You should be able to get a good start for 200 dollars with turner. Also be warned incubating eggs can be addictive. I bet you will start to buy eggs on
ebay and keep on going.