Yes, you can use different brands of hard drives in your Thinkpad. Infact, there is a user here named brentpresley, he has several drives available for great prices. I picked up an 80GB 5400rpm drive from him for $85 shipped. I have also purchased ram from him on more than one occasion. I highly recommend him.
Non-IBM optical drives are very hard to find that fit the IBM laptops. Most (>99.9%) of the DVD burners out there are 12.5mm in height, but the IBMs use ultra-slim drives (9.5mm) and that makes them much more expensive and harder to find.
Does anybody have a good suggestion for a non-IBM (=>cheaper) DVD-burner for T43p's Ultrabay slim with larger write-speeds, still having DVD-RAM possibility? Preferably in europe, but US would be ok as well..
Thanks a lot!