The most optimal variant - is to send us your project as CUBASE 3 of CUBASE 4 project. 
OR, to send us your project files according to the following specification:
1) 44100, 24 bit.
2) EACH TRACK AT MAX VOLUME, BUT NOT EXCEEDING 0dB peak.
3) All instrumental parts should be already processed with Effects.
4) Name your filles correctly. E.g. kick.wav, snare.wav, synth stab.wav, etc.
5) Mention track tempo in BPM.
6) Provide MIDI tracking of all project parts.
7) Provide track PREVIEW in 160kbps MP3 format.

The files for mastering should be provided as follows:
1) 44100, 24 bit.
2) Peaks should not exceed -2 / -3 dB!
3) ALL MASTER BUS PROCESSING SHOULD BE SWITCHED OFF IN YOUR SEQUENCER.
4) Name your files correctly. E.g. DJ Felix – Cool tune (Orinal mix) 128 bpm. wav.
5) Mention track tempo in BPM.
6) Provide track PREVIEW in 160kbps MP3 format.

MASTER VOLUME OPTIONS:
1) “QUIET” – all the dynamics maintained, but sounds subjectively quiet. RMS (-14dB).
2) MEDIUM VOLUME. RMS (-10dB).
3) LOUD (PUMPING). RMS (-7dB).

The materials for software to analogue/VA-synths conversion should be provided as follows:
1) PREVIEW of original software synths parts.
2) MIDI tracking.
3) PREVIEW of the track with similar part at 160kps MP3.
4) Mention track tempo in BPM.