You don't need or want the ones with fans. The basic model 1602, I believe it is, is all you need. These work good for when you have a cool place and don't want temps to drop below the set point..... but they will not cool down the temp inside the incubator if the temp climbs higher than you'd like. If you have a spot in your home that stays at a constant temp close to the incubation temp you'd like, just place the eggs there. People call this the 'closet' method.
I have one of the MR-148's from LLL Reptile. It works great where I am at because my temps are all over inside my apt. So I don't have to worry too much about the eggs getting too cold or too hot.
With any option you choose I highly recomend getting a 'indoor/outdoor' digital temp gauge that can tell you the max/min temp. This way you can monitor the temps swings of the eggs. I use one from Lowe's that is about $14. It does Humidity and temp, both in and outside probes. You can reset the min/max temps with the push of a button.
