I use Text::Unaccent::PurePerl for this sort of thing and am quite happy with it. The documentation is also rather clear about what exactly it does, so you can see whether it matches what you want or not.

While looking up those docs just now, I also stumbled across Text::Transliterator::Unaccent which appears to be a configurable solution using unicode attributes, but I haven't used it, so I can't comment on how well it actually works.