Custom Search Form with or without search module?

I have a custom module that I want to make searchable. The thing is I don't need any kind of keyword search. In fact it won't even search the node table. It will search based on three fields in the custom table I defined. I'm wondering if there is any reason to bother with the search module for this. The hook_search docs say you can define additional form elements with hook_form_alter, but I'm not sure if the search module would even offer me anything.

I want my custom form to show up as a stand-alone node (with no tabs or keyword textfield), and also at the top of the search results so the search can be modified.

Anyone with more experience have any advice?