As the monitor size increases so does the power consumption. The brightness level of the monitor also has a relation to power consumption. Recently monitors with LED back lights have come on the market.  These use significantly less power than the older models with ccfl back lights.  

 

Typical 14-15 inch, ccfl monitors use 20 watts on average & typical 17 inch ccfl monitors will use 25-30 watts .

 

A typical 19" LED monitor uses only 15watts while a 24" will use about 26 watts.

 

The Viewera monitors listed below are all CCFL and the rest are LED.

 

In general the specifications for monitors in the same size class are similar regardless of price. The main difference seems to come in the design of the frame and base. The base is removable on most models to facilitate bulk head mounting. Some monitors have a base that folds behind the monitor rather than coming off.

The following monitor models are a few of many available on the web and at local stores. They all use 12 volts for the power input and are standard home/office models. You should check with the vendor to verify that the model is still powered from a 12 volt power brick as some manufacturers will keep the same model number but change out the power supply.

Some available 12 VDC monitors as of 01/01/11

 

Newegg
ViewEra V151HV-B Black 15"

ViewEra V151BN-B Black 15"

ViewEra V172BN-B Black 17"

ViewEra V191HV-B Black 19"

ViewEra V191BN-B Black 19"
Mag Innovision GML1920/GML2226/GML2427  Have VESA mount and 12 volt
Samsung BX2035/BX2235/BX2335
Samsung BX2050
SAMSUNG BX2031
SAMSUNG XL2370
LG E1950T/E2050T/E2250T

Sceptre E246W-1080P
DoubleSight DS-90U 9" USB monitor