Firstly, if it were me I would have them properly mastered - even though I mix and master myself, I find I cannot master my own mixes as I am too close to the project & tend to revert back to multitracks & redo the mix rather than simply let it go & get on with it. Maybe it is just me but I honestly cannot find the objectivity to deal with my own work.
As far as it goes though you have a few choices.
1 - Master it in Cubase (why not?) and set your crossfades there. Add markers at the right track points & export as a CSV file (or else write down the timings) and make the CD in a standalone app like WaveLab or similar.
2 - Again, Master in Cubase & use the HOFA DDP plugin (or the standalone) for the CD creation
http://hofa-plugins.de/pages/start_en/hofa-cd-burn-ddp_en.php
It’s got a learning curve but will get you there.