There are some basic specifications that this project should meet:

player software running on linux
standalone device, maybe two decks on one cpu or one cpu per deck
music input from normal audio cd. later maybe mp3-data-cd support.
cueless playback from song to song to be able to play seamless bass-loops with repeat function
graphical output on lcd-diplay or on tft-flatscreen computer monitor

velocity input via state-of-the-art turntable
pitch range at least +/- 10%
manually operated turntable
33 1/3 RPM and 45 RPM
robust turntable case
turntable also usable for normal LP playback via needle

technics 1210 look (would be nice)