First of all, I would like to thank you for choosing the user name you did. Rikki-Tikki-Tavi was one of my favorite cartoons that they used to only play on TV about once a year (back before the Youztoobs they got these days). I have to watch that cartoon again now.
About your question, in the left-hand margin if you scroll down a little you will see a heading called
Items/Equipment and directly below that a link for
Search which takes you to the advanced search page only usable to premium members.
From there you can enter you search criteria and fiddle with the filters to look for upgrades. In the past the search page hasn't always worked 100% accurately, and even now in my experience there have been items that for one reason or another have not turned up in search results and should have. Regardless, it's a nice feature and should be what you're looking for.