Like mentioned most DSLR bodies are all built with the same durability, the main difference in durability is Metal bodies over Plastic. A metal body will out last a plastic body put under the same conditions. Metal bodies are on the higher end, more expensive bodies (at least for canon). The T2i is a entry level DSLR, It's a great camera, and can be picked up used for about
$550 on adorama right now, with a grip. If you had more cash the 50D Less Cash the Rebel XT.
As for the lens length, a lens converter is the cheapest way to get length. A 200mm can become a 400mm for about $150-$200 (used).