In our area, 120 head of cows simply isnt enough to sustain a family without having another job in town. Can a guy make some money? Sure. But not enough to only have the cattle as a source of income. Your idea of keeping calves longer than weaning will pose a new set of challenges as well. How will you feed them? What is your cost to get them to finished weight? Will you have to run fewer mother cows in order to keep calves past weaning? Diversification with ag-tourism, hunting leases or outfitting, ect also have their own issues. Dealing with people can be a huge challenge even if they have money. Think "City Slickers"! Is that worth it to you? I suggest you look at simular sized operations in your area and see what works and doesnt for them. Your climate, ranch location, experience level and many other factors will make me answering your question impossible as i only see what works here. I hope i dont sound negative. Because with hard work, passion and ingenuity you can get it done. But it is an uphill pull. Good luck!