Thanks for the answers!!!
Right after installing Win 7, updates, drivers and basic software (antivirus, PDF reader, etc.) and making sure everything worked fine I made a system image using Win 7 tool, stored the image in a external HDD and it took a little less than 30 GB in space.
Due to lack of time I wasn't able to thoroughly check your recommendations but their are noted, I'm planning on installing a bunch of application and experiment a little with them, so I'm really gonna need something more flexible than Windows integrated tools. Clonezilla and Todo backup seem pretty solid recommendations, definitely gonna check them out in the future. Also I read some really good thing about Macrium, maybe I'll give it a try as well.