The e46 (that's the BMW model name for a 3-series that year) 330i engine is very powerful and an overall nice engine. I haven't driven one personally but my brother once drove one, and it's a really good engine. Lightyears ahead of the 320i. And it will last long if you maintain it properly. The Touring is generally a good choice already, as it's sporty and can load a lot. The X-Drive is my favorite AWD system...
Are you planning on keeping your 850ci?