One Xtian forum is for discussion. When people of a different viewpoint come trolling, as in will never give on their views and legitimately are just being evangelical of whatever their worldview is, and aren't relevant to the OP and discussion, such as the bratty comment above, it is a legitimate report. I don't have time, energy or inclination to deal with the Xtian infighting, let alone the atheists, but other mods do. OP was asking a point of Jewish law. Bratty's religious thought has nothing to do with it.
Orthodox conversion is more rigorous. And the rabbinic authorities with influence tend to the Orthodox side. It's not so much which branch but which rabbi.
actually since judiasm passes from the mother you could claim jewish as your religion. you cannot become an orthodox jew unless your mother was full orthodox. my sister was a nun, then before her final vows (after three years) she saw christianity as too limiting, then she went jewish, and after a time found it's all about law and maintaining a discussion with an absentee father - you're not gonna find comfort being a born again jew, nobody does. but good luck i would suggest seeking truth not advertising from big sales outfits - sounds like so far you are going to the outlet mall of religious experience
Orthodox would most definitely accept him, if he were to go through with an Orthodox conversion. I think he would be taken far more seriously than if a woman was doing it for marriage, which they do accept (albeit with skepticism at first.) It's a mitzvah to accept converts as full-fledged Jews.