You're talking about only 64 nodes right now. Your storage and IOPS requirements are not huge. A lot of mid-size hosting companies will give you fantastic service at the 10-1000 servers range. If I were you I'd talk to someone like https://www.m5hosting.com/ (note: happy dedicated server customer for many years -- and I'm sure there's similar scale operations on east coast if that's really what you need) who have experience running rock solid hosting for ~100s of dedicated servers per customer.
I suspect you may just be able to get your 5-10X cost/month improvement (and bare metal performance gains) without having to take on the financing and hardware bits yourself.