16 Stone if I'm correct is 224 US pounds. That's not really heavy at all.
What kind of riding do you want it for? ..... racing, sport, or touring etc.
I divide this answer into 2 parts. The frame. The wheels.
Road bikes don't have weight limits. Wheels need to be built well though. A Professional built wheelset that "stands" is worth it's weight in gold and will make most frames worthwhile to ride. By "stand" I mean it stays true and round for the user once it leaves the wheelbuilers hands.
By todays standards though, I would be considered "old school", as I like 3 cross double-butted spoked wheels made by hand, not a machine.
Prebuilt bike these days though generally come with low spoke count wheels and radial lacing. I have no idea how they would hold up for you.
I'm a hare taller than you, and I have been your weight years ago when I rode a Reynolds 531C racing frame and 36 hole 3X wheels and had no problems with the frame. So, any frame will be fine for you.
If you get a prebuilt bike though, try to get it from a shop that can make sure the wheels are true and round, and have the spokes pre-stressed, BEFORE you ride the bike. If they don't know what this is, find someone who does. This will make your wheels more durable from the start.
That's about all I can offer you, as I'm not up on pre-built bikes anymore, I put bikes together part by part these days.