I have never noticed one soluble oil was better than another, I usually tack it on the end of an order for something else to avoid carriage. Currently using Multi-Cut G which does seem disinclined to rot.
Modern suds pipework usually ends with one of those bendy hose things that stays where you put it and a nozzle.
You will need splash guards to catch suds. As soon as suds hits a spinning chuck it goes everywhere.
Two nozzles are better than one, coming at the tool from opposite directions.
The cheap Chinese bendy hose leaks if you stray not very far from straight.
If you use a nozzle you need to filter out everything that will not fit through that nozzle, I use Koi carp water filter bags..
You will need a Wet'n'Dry vacuum cleaner with a crevice tool to empty out your T slots between jobs.
Your suds return hose will block, put a brush over the entrance before you hit it with a blowgun or get a face full.
As the level in your suds tank goes down you will top it up with water, try to remember that eventually you will need to add more oil.