If the authorized resellers were companies I'd never heard of, I would hope that would raise flags. But, yeah, especially at a smaller company, getting an official-looking company check and told to use it to get myself set up and expense it when I started would seem pretty normal.

Though it's been many years since I've traveled to interview, I was always paid by check for anything out of pocket. (Except for a 3 letter government agency who paid me in cash.)