We have used Sonlight Core 3/4 and 4/5 along with My Father's World K.
We are currently using Sonlight Core K with my 4 1/2 year old son.
I also plan on adding in Rosetta Stone Spanish, which we have and I highly recommend. My husband and I used it for 6 weeks or so before a trip to the Dominican Republic and we were both amazed at what we learned. It makes learning a language fun and for us we tried to 'compete' against eachother to get a higher score! I am planning on having to do this with my son for a while, at the moment he doesn't like the headset on his head.
We will also be adding in some Geography. We love the resources from Geography Matters. I haven't finalized any plans, but we will do some from Galloping the Globe along with other books that we have and from the library. I think we will start with a little introduction about maps and the world and then focus on different continents. A few weeks per continent starting with North America.