Lighting Direct has a site online. You may be able to find the item you're looking fro here. This site seems like it carries many different parts in a variety of assortments.
It's generally impossible to clean ceiling tiles. Just buy a replacement one.
Scanner replacement globes can be purchased from the manufacturers via their customer service lines either online or by telephone. Additionally, Amazon and Staples stock a wide range of spare parts including globes for scanners.
The Lowe's website has a guide on how to find the best replacement storm window glass for you. You can purchase some from there, and of course Home Depot.
Depending on how large of a replacement you need there are a number of sites available. Try Crystal glass and their website for more information. They usually have good service and warranty.
You can find replacement glass for your broken windows at your local building stores. It is an expensive and difficult job if your not accustomed to doing it. I would suggest hiring a carpenter to help you out.
Salvage yard?
Check out in amazon.
A commercial glass door would be purchased from a window replacement, or window repair compnay. Where to buy depends on where you live, and where there are local companies near you.
Any glass shop that makes frameless glass doors can do your table. So look where you live for glass shops that make glass doors.
Usually, the solar cells are attached to the glass via an adhesive membrane to prevent condensation. If the solar cells can be removed from the broken glass, simply take a shard of glass with dimensions to buy a matching replacement. The problem you'll face is how to keep the replacement glass from the effects of condensation.
You would take a piece of the glass to a glass store and custom order the glass top. It can be a bit pricey, but you need the thicker, tempered glass.
Spare parts for ceiling fans can be bought at any local miscallenous store or online at Amazon, eBay and many other stores. One should consult an expert before personally repairing a ceiling fan and other devices.