It is absolutely the Jewish way to meet a Shidduch thru a Jewish dating site.
As far as using it in lieu of a mentor, get yourself a live mentor, even if you end communicating with this life mentor over e-mail or telephone, and even if this mentor who knows you is in Israel and your in the USA, or vice versa. But the mentor has to be familiar with your situation and circumstances, and be someone whom as soon as s/he hears from you, will immediately know where you left off last time you touched base, and needs no recapping each time you touch base.