I tried projectors and found them difficult to use since my hand creates a very dark shadow that blocks the area I need to see. I also found it almost impossible to get the drawing image perfectly square on the panel. If you need to retrace an area, getting the projection set to match what you traced originally is a lesson in futility. Additionally I could not see my tracing marks once applied.
I switched to printing out transfer sheets then transferring the image to the surface. I will never go back to the projector. Scan your preliminary drawing then size it to fit the exact dimensions of the painting or if you are tracing a photo, do the same. If your printer won't make a big enough transfer sheet use the tile function (Adobe Acrobat is the easiest for me) to create as large of a sheet as you need, taping the multiple sheets together than applying graphite or pastel to the back so you can trace the image onto your painting surface. I have made 48" wide transfer sheets that worked perfectly. The best printer / scanner I found for the job under $200 was the Epson Workforce series with a 12x17 scan and print capability. The WF-7610 can be found for $150 shipped from time to time.
Most after market inks and carts are not that great. Some will totally ruin your printhead. If you are going to be doing a bunch of printing, I would strongly recommend that you get after market tanks and inks from either http://www.precisioncolors.com/
Some folks like projectors. Hopefully you will get some good advice on which ones they do like. Make sure it has keystone correction, is bright enough to see clearly without having to be in total darkness, and will focus at the distances you will need.