Duplicators burn discs with the same kinds of burners that PCs use. The duplicator is built from a power supply, a case, a controller head that fits in a 5.25" drive bay, a bunch of DVD drives, and a few power splitters.
Replicators stamp into the discs.
Most of us build/buy duplicators, but for large quantities (1000s of each disc) You may want to order duplicated discs. It depends on the mix. For 50,000 of one disc per year, go with replication. For 10 of each disc, go with duplication.
I do not print Your quantity of discs. I use a couple of Canon MG5320 inkjets. They have a plastic tray that loads a single (InkJet Printable) CD at a time.
Other printers will change the discs for You. I have no experience with these printers. Most people I know just run large groups of Inkjets.
Buy waterproof inks. It does cost a few bucks extra, but it's worth it. It does not look professional when ink smears on a CD.
Buy generic inks off Amazon. They will save You money.
When You find an excellent batch of ink carts from a reputable seller, buy up to a 2-year supply so You do not have to keep experimenting. After 2 years, they are dried out and no good.
Occasionally, a cheap ink cart will mess up a print head. It's a cost of doing business. Get Your money back plus the cost of the printer from the scumbag who sold the defective ink cart.
MeritLine.com has lots of inkjet printable discs for sale at not-horrible prices.
You will often be in line at the local store that is running a sale buying a basket full of cheap discs to save money, or buying one spindle at a time, and going through the line for 6 hours straight.
Not all white CDs are inkjet printable.
For inserts, get a couple of used HP Color LaserJets off CraigsList and buy remanufactured toners off eBay. I suggest something like a LaserJet 4600, 4700, or 8500. I've used these for years, and they rock.
I'm not sure where to get the small slips of glossy paper that look good.
Test everything. Don't run 1,000 bad discs.
You might get into legal issues if the MAFIAA decides to harass You. If this happens, a 12 gauge beats a lawyer.
I hope You are good with layout design, and Photoshop or a Photoshop clone like www.GIMP.org. You need to be to design disc labels.
Printers come with their own quirky disc-printing-programs, but Photoshop or the GIMP is still necessary.