For thermometers and humidity meters, these are ones I have used and/or still use, note that I always have a least two meters in the incubator to cross reference... They are all pretty decent for the price...
Do note that low cost humidity meters are generally not that accurate, but they can give you a very good reference even if not fully accurate...
http://www.walmart.com/ip/AcuRite-Digital-Humidity-and-Temperature-Monitor/16888914 I use these all over the place, inside the coop, inside the brooders, inside the incubator
http://www.amazon.com/Zoo-Med-Economy-Thermometer-Humidity/dp/B004PBB1JE This is in my incubator right now as a second reference, i like the low profile as I can set it on top the eggs...
http://www.ebay.com/itm/Digital-The...el-Mount-HG-/291525404992?hash=item43e044a940 Note that is just one of many
Ebay sellers selling it, not a seller recommendation just showing the item... I use this one in my 'fake egg' to monitor a simulated egg internal temp... My fake egg right now is a 3oz baby bottle, nipple upside down, with about 2oz of water probe is inserted through the nipple into the water... And of course it requires a power adapter as well...
http://www.walmart.com/ip/Aquaculture-Glass-Aquarium-Thermometer/45081765 I have several of these, very, very decent for the few dollars they are in the store...
At the end of the day it's a much better practice to monitor air sack development and/or weight loss of the eggs then worry about what a humidity meter says...