First off, welcome to the hobby! It can be quite a blast and will relieve you of any extra money that boggs your life style down.

Anyway, your list looks like a good start. The Leman Russ is a great versital tank that will serve you well. Right off the bat I see a problems, namely that the Weapon team with the Las Cannon is illegal, they have to be taken in sets of 3 and part of a platoon which it looks like you are not running. I am guessing those troop units are Veterans, right? Otherwise you would have to get a platoon comman squad and another troop since the 3 flamer squad can only be fielded as Vets. So go ahead and swap that Las Cannon for the Heavy bolter or put it on the shelf till you can use him. My other thought might be to chose a role for your Command Squad such as do you want them to be a tank hunter or a troop killer. I am not usually a fan of duel purpose squads, so either drop the flamer or the melta.
You have a good start. Of course Chimeras are great for mechanized infantry since they are only 55pts. They are good at getting your heavy hitters into combat but are wonderful as a heavy weapons platform. Not only that but the retail price I believe is coming down a bit and the new model should be coming out in a couple weeks.
Good luck, homie!