Put a new touchscreen with a best definition

With the original eos, ion, and element, you are limited to the ELO 15 and 17" touch screens.  With the eos ti and gio, you have many more options (including some 19:9 ones) See http://community.etcconnect.com/wikis/products/touchscreen-monitors.aspx for more details.

but since the beginning we have a 19 " 4/3

but since the beginning we have a 19 " 4/3

For touch monitors with the original Eos you are limited to ones that use ELO's AccuTouch 5-wire resistive touch technology.  You can use their product selector tool to find these: http://www.elotouch.com/Products/LCDs/selector.asp  (choose AccuTouch in the Touch Technologies category to filter the results). 

It looks like there are only a couple widescreen options with the largest being 19".

thanks everybody !