Servers, it depends on if used is cheaper, if HPE is cheaper or DIY is cheaper. Dell nowadays is more expensive than HPE but now Dell is the superior product, whereas in the 2000s HP was the high-end.

For colocation, I use Microtronix. They don't have the greatest network but are excellent for the price and have great support. In the past I had DediPath from a now-sold VPS host and DediPath (before they folded) had slow support.