I´m 6 5. (200 ibs) Since your friend is 50 ibs more....
I would reccomend (for the US market)
A Scott Speedster S1, s2 or s3 (depending on budget) size XXL with custom wheels mavic cxp 33 rims (stiffer than open pro) and 36 spokes in a 3 lace build. Ultegra hubs or Campy Veloce depending on what gears you want.
A Trek 1500 in size 63 again with the same custom wheels as above
A non carbon cannondale frame caad 8,7 or 5 in size 63 again with the wheels mentioned above. (The Caad 5 is the stiffest and cheapest I beleive the model name is s500).
A Specialized Allez in size 62 again the wheels custom (which is not by any means expensive)
Stay away from getting a carbon frame (he is just too heavy).
Titanium is really nice but also very expensive and at that weight potentially flexy.
Stay away form the very nice looking (but that´s all they do) design wheels like Ksyrium, Bontrager, Campy, Shimano you name it they are too flexy for his weight, even at 200 ibs thay are often too flexy. Some insist that they are not but I strongly disagree.
If by any chance you should stumble across Brands like Principia or Boreas (size 63) they are very stiff bikes and would also do the trick but thay are very very hard to come by in the US. I mentioned some ready availiable brands in most US stores even though they might have to order your (his) size.
Also while youre at the bike store pick a store that offers a fitting, So that he gets the correct setup on the bike. (Saddle height, stem length, handlebar width, crank length, cassette setup, double or tripple crank). Dont accept "well that looks about right" from a shop owner that has not measured you (him). It might cost you a little bit more but the end product will fit and that´s definetly worth the extra cash.
As to grouppos you will do very well with Shimano 105 or Campoagnolo Veloce, but dont go lower than that.
You could go up a notch to Shimano Ultegra and Campagnolo Chorus.
If money is no option there is ofcourse Shimano Dura Ace and Campagnolo Record but both groups are made with weight saving in mind and not much point in that when youre 250 ibs and not competing (except for the feeling of having a high end product) In functionality Ultegra and Chorus are just as good)
Have fun riding!