Actually UA might have some 767-200ERs, since these aircraft flew Trans-Atlantic, I believe.

As for First Class on the two-class 767-300ER, it is not worth the money. I have been in it as part of a longer itinerary and the seats, while the First Class design, are only one inch wider (19" vs. 18") then the Economy Class seats and pitch is 38" vs. 35" in Economy Plus or about 40" in the Exit Row.

I found the Exit Rows to be a much better value, especially 21ABHJ, though 20ABHJ is good, as well, just lacks some recline.