I just finished this one. The first needed tweaks and I needed more space. Its a 2x4" on top of a 2x8". Just wanted a little deeper holes and I got tired of going to my storage. Just seems to work better. Also, on the bottom, far sides are holes for tiny RDAs without being recessed and the ability to put a topper in upside down to work on it. I sometimes need both hands and had no way to work on the coil without draining the juice. Those holes are 3/8" and the drip tip fits well.

Hope it gives ideas

Hope it gives ideas