Now I'm looking to buy a bigger rig or cabinet, something along the lines of 50-150 Th of mining power.
The Spondoolies SP50 was going to be a 50TH (appx) machine in a 11U (I think?) rack mount, but Spondoolies either never sold any or sold a VERY few to a large mine before they went out of business.
Nothing else came close that's even remotely current.
As far as I know there isn't anyone making rack-mount mining gear at this time, Bitmain seems to given up on the idea after the S4, Bitfury doesn't seem to be selling "miners" any more other than their "container" gear, and none of the other miner makers I am aware of have ever made a rack-mount unit at all.
Given lack of production availability at ALL of the very few foundries that can make current-gen mining chips, I don't see ANY possibility of ANY mining chip maker even THINKING about leasing their gear. They can't get enough chips to SELL as many as they can make, why mess around with leasing BS?