Is your planned tour one that requires particularly good lights? I've usually just taken a small battery LED headlight that doubles as a camp flashlight and the usual blinky taillight. But then I'm not really planning on much night riding - it's just good to have along in case the need arises.
If you do go the DIY route with lights I'd suggest building them well in advance of the tour so you can have them on your bike for some extended rides under various conditions. Nothing like a good field trial to determine any weak points in the mount or electronics that may fail due to vibration, rain, temperature variations, etc.