At the risk of overwhelming you with information, I'll tell you my setup. Like others have written, there are MANY, MANY options you can go with because the format is so adaptable, so take my setup only as an example of what you could do.
1. For bellows, I use the Canon FL bellows in conjunction with my Canon FD/FL adapter. The FL mount is the older breech lock mount, which is shared by the early version of the FD mount before they went with the bayonet mount. The FD adapter should work seamlessly with either FL or FD lenses/accessories.
2. For lenses on the bellows I use a variety. I use the Canon FD 50/1.4 either normally mounted on the bellows, or reversed using the FD reversing adapter that comes with a 52mm thread. On occasion I also use my Panasonic 20/1.7 lens either reversed or normally fitted through a custom MFT-to-FD adapter. I also use my enlarging lenses (Fujinon-EP 50 or EL-Nikkor 40) with an M42-to-FD adapter, then an M39-to-M42 adapter ring to fit the lenses themselves to the adapter. I also use microscope lenses through an RMS-to-M42 adapter that I then fit to the aforementioned M42-to-FD adapter on the bellows.
3. For lighting I use a variety of sources depending on the magnification I'm working with. I don't have a TTL flash, so I use an off-camera Vivitar 285 flash unit with either an optical slave triggered from my camera flash, an RF slave triggered by a remote flash trigger on my camera hot shoe, or through a TTL cord. For high magnification work I use a Dolan-Jenner Fiber-Lite with light guides.
4. Supposedly the TTL function doesn't work very well with adapted lenses in manual mode because the camera doesn't know what aperture setting you're using, so you're forces into using manual flash anyway. I can't verify that, but others like Godfrey, Vivek and others have quite a bit of experience in this so they can chime in. I think they may have fixed that in the later releases of the firmware, but I simply don't know to what extent.
Hope this helps.