Well, I wasn’t going to chime in because what you started out with is fine with the exception of a few minor details — and a one fundamental major faux pas to my mind that nonetheless falls into the “Oh, honestly Auntie, everybody does it!” category (and no, it isn’t the website R.s.v.p.: with that, I have no problem.) But since I’d argue with some of the details other folk find worth commenting on, I’m going to weigh in.
So. Basic principles of formal good form: “less is more”, honest English phrases are more refined than foreign phrases, George Routledge and the original Emily trump both Martha and the current Post Institute, and a lady’s name is never written up jointly with a man’s name unless she is married to him.
Mrs. Brides’ mom full name
Mr. Brides’ dad full name
— this is the best you can do if your father insists on being named: separate lines and no “and” so as to avoid implying that the two hosts are married. Most properly, he would kindly transfer funds to your mother to allow her to host your wedding in style while gallantly remaining in the background — hardly a twenty-first century trait however admirable such gallantry would be. And besides, as I have been told, “everybody does it”.
Request the honor of your presence — you don’t need to capitalize “Request” as it is in the middle of a sentence
At the marrige of their daughter
Rachel3212 — you get to use your middle name or names here, if you wish
Fiance full name — since this gentleman is unrelated to the hosts, who refer to themselves by surnames and titles, the hosts would graciously acknowledge his title too, and refer to him as “Mr Fiance full name”
Saturday, the twenty eight of January (should the “t” in twenty and the “e” in eighth be capitalized?) — you don’t need the comma after Saturday, you do need a hyphen and an “h” in “twenty-eighth”, and no, you do not capitalize the “e”. In keeping with the whole “less is more” theme, you absolutely do NOT need to add “in the year of Our Lord”.
Two Thousand and Twelve — nor do you capitalize the numbers in “two thousand twelve as they are not proper nouns and are in the middle of a sentence, and you can do without the extra “and”.
At Four O’Clock in the Afternoon — unless your friends could imagine you getting married at four o’clock in the morning, you can forego the “in the Afternoon”, and as above since none of these are proper nouns, they aren’t capitalized.
Reception to follow at name of venuename of location — these two lines can go in smaller letters in lower left if you are running out of space; and you don’t need to say “to follow” as that is implicit.
Please R.S.V.P. by (not sure when yet!) on our website — Less is more, remember? If you are not going to use the English “The favor of a reply is requested by <date>”, then just use “R.s.v.p. / http://www.theknot.com/ourwedding / by <date>” in small letters in the lower right corner. Don’t go for the extra reception card; it is unnecessary, and therefore overblown, and therefore pretentious.