If you want to be closest to the parks (if you plan on walking), go for 14 or 24 (we stayed in 24 which was great for us). If you'd rather be closer to the main building (shop, bar, breakfast, reception and bus to parks) go for 40 or 49. Pretty sure the rooms are all much the same, but some blocks have an ice machine and vending machine (Sorry I don't know which ones off the top of my head, but you can use them even if you're staying if another block).
My DF called Cheyenne a couple of weeks before our trip to request a specific block, and they were very accomodating and gave us exactly what we'd asked for!
from whichever room and block you are in at the Santa Fe, you are only 2 minutes walk at most from the room blocks bordering the river and bridge over to the Cheyenne side of the path and onto the Village and parks.