If you are thinking about fitting new pickups, you'll probably have to enlarge the pickup routs as the mounting tabs on the kit pickups are a smaller than standard and I had to widen the end cut-outs considerably to get them to fit in. It's all hidden by the pickup surround, so you can do it at the end (I had to), but you might want to do it now before you put any finish on.
Now is also a good time if you want to fit an internal block so that you can mount a strap button on the side of the upper front bout. It's a better place to put one IMO than on the heel. If you are interested, have a look at my ES-3 build diary as I put in a few pictures of me adding a block inside. It works very well.