According to Tom's Hardware benchmarks the 3850 beats the 1950pro in most games, especially at higher resolutions, so it looks like you are doing the right thing.
In fact I got a free copy of PCA through the letterbox this morning, and in the graphics cards group test the 3850 gets a PCA Recommended. At that price point it's unbeatable.
I can see no technical difference between the 2 cards you link to. Maybe the Sapphire card has a better warranty?
I'd probably go for the £88 card from Aria