We have made custom versions of the LED transilluminator with different LED wavelengths. We just made one with 400 nm LEDs for example, and we have also made one with green LEDs (523 nm). We are planning to make a white light version shortly for viewing/imaging visibly stained gels.
As far as the near infra red (700 nm) wavelengths, I don't think we have made this before but it is possible. The trick is finding the right LED. For the transilluminator boards that we use, the LED would need to be a through-hole LED with standard 3 mm or 5 mm LED pin spacing, in the wavelength of your choice and have a viewing angle of 120 degrees or more (for uniform lighting).
Electrophoresis and Gel Imaging