Hi Mikecd,
While I was looking at your rack layout and writing my reply to you, you wrote another message :-)
Don't use the rack power supply for powering your Deluge and your Arturia Keystep; you are going to need the power of the rack for the modules themselves...
Since you consider to DIY rack then go for a large rack, 3 or 4 times 168 HP or something like that and add power supply once needed. In that way you save some bucks as you already mention it and at least you will have some space to grow with :-)
Please check my previous post too.
Good luck and kind regards, Garfield.
Edit: Removed typo
For review reports of Eurorack modules, please refer to https://garfieldmodular.net/ for PDF formatted downloads