I was 23 stone when I got a road bike in April.
I got a Cube Agree (ultegra SL thorughout) which was supposed to come with Eastons EA50's, the LBS swapped them to Fulcrum Evo 5's, 20 spokes front, 24 rear.
Not had a single problem with the bike. Now have a winter bike too running some similarly priced wheels with same spoke count but round/stainless spokes, again no problems at all after over 2000 miles on the two combined (1500 on the Cube). I now weigh 19 stone.
I seriously wonder if a real budget bike would have coped, but who knows really?