The Russians had some really interesting reactors tested, aand the one on onboard the Alpha's was also quite an interesting one.
093 against LA? I don't think the 093 would be on the winning end, but as Sea Dog said, there are to many unknowns. If the 093 is operated by an experienced crew and is fighting in homewaters it could probably beat a LA-class boat. The Seawolf and Virgina is way in front of the LA when it comes to both silencing and sensors, so I wouldn't recommend trying to pick a fight with one of those...