I'm wanting to make a standard sized touchscreen keyboard

More information would be neccesary help you complete this. Some things that would help are:

1. Is it touchscreen with a display behind it? Or is it an onscreen keyboard?
2. How are you looking at using to control it?
3. When you say custom keys do you mean for launching programs or layouts?
4. By wireless do you mean bluetooth or WiFi?

To further explain:

A touch screen with a display behind it.(i.e. much like a touch screen cell phone with a digitizer and an LCD)

I am not sure what or how to control this widget but I think an Android base or even something along the line of the mobile Windows phones and tablets.

A keyboard is normally static the keys are always the keys, but what i am thinking is more of, one million keyboards in one screen. Having available all languages and set ups for any keyboard, also custom keyboards for individual games such as W.O.W. or any other game or drafting program where not all the keys are needed, where you can also set up macros short cuts for the program itself or have a keyboard setup just for kids and learning. all keyboards can be created by one and all and be downloaded as app's from places like Google play or Windows store. this could also be set up for the handicapped large keys or pictures for keys or motion gesture typing for people with less motor skills and even handwriting recognition.

I was thinking more of blue tooth as that gives the keyboard more range but I was also thinking TV remote capabilities like the universal remotes.

Sort of an elongated tablet

To further explain:

A touch screen with a display behind it.(i.e. much like a touch screen cell phone with a digitizer and an LCD)

I am not sure what or how to control this widget but I think an Android base or even something along the line of the mobile Windows phones and tablets.

A keyboard is normally static the keys are always the keys, but what i am thinking is more of, one million keyboards in one screen. Having available all languages and set ups for any keyboard, also custom keyboards for individual games such as W.O.W. or any other game or drafting program where not all the keys are needed, where you can also set up macros short cuts for the program itself or have a keyboard setup just for kids and learning. all keyboards can be created by one and all and be downloaded as app's from places like Google play or Windows store. this could also be set up for the handicapped large keys or pictures for keys or motion gesture typing for people with less motor skills and even handwriting recognition.

I was thinking more of blue tooth as that gives the keyboard more range but I was also thinking TV remote capabilities like the universal remotes.

Sort of an elongated tablet

A wirless display through bluetooth is a little unrealistic, unless the keymap and icons are not edited often. For the touchscreen I advise researching and finding a touch screen panel and programming it with the arduino, because most touch screens are only four or five wire connections.

So the leg work I've been doing:

custom sized touch screen panel prohibitively expensive

custom sized lcd panel prohibitively expensive

I've started looking into a 17 inch moniter with a resistive overlay to get the same effect

and making it usb/vga attached until I get it working and then go wireless non blue tooth

I have aslo found a keyboard program from Comfort Software "onscreen keyboard"

(But haven't decided yet)