Steering dampers are fairly limited; aside from the expense of OEM (which I prefer) there is Monroe @ about $30 which most seem to do (including myself).
What do you mean by door locks? Explain the symptoms/problem. The whole mechanism is known to wear - there are bandaids and fixes (replacement, $$$). Lots of threads on this type of stuff, search on that one.
I replaced my passenger seat belt, bought from ebay, glad I did it!
As far as the bumper goes, I don't think anyone on here has that ebay replacement - you may be the pioneer there.