Aside from more bottles and trays you may want to get a paper safe. Its not a necessity since you can use the original boxes but it makes life a little easier. Another nice thing to have but also not absolutely essential is a grain focuser for making prints. You can always use your eyes for focusing but this tool ensures your prints will be critically sharp. It is also good for testing the allignment of your enlarger and checking edge and corner sharpness. You can also use it to find out which aperture of your enlarging lens provides optimum sharpness.