The cpan-testers-discuss mailing list would be the best place to ask about stuff like this. But yes, SQLite is a good choice. MySQL is a good second choice as it's fairly commonly installed. Anything more exotic probably won't get tested much, or, indeed, at all, because setting up things like Oracle is a pain in the arse.
in reply to Re: How to do automated tests of a database centric CPAN module
in thread How to do automated tests of a database centric CPAN module