Infrastructure and Agile/Scrum

I have coached teams doing what you are doing, and they have benefitted greatly from Scrum.  While infrastructure is not the most "vanilla case" for Scrum, it can definitely benefit greatly from Scrum.  Having said that, since you are dealing with a non vanilla case, it will likely take a Scrum expert/coach to teach your team how to do this well.

Having said that, what you are describing here has some overlap with DevOps, and the DevOps movement is about bringing people like members of your team onto Scrum software teams so that they do not have to rely solely on an external infrastructure team.  See here for more:

https://devopsinstitute.com/wp-content/uploads/2017/09/Scrum_DevOps.pdf

With respect to things like ordering servers, Vanilla Scrum teams have this same challenge, it's called an "external dependency" (meaning "a dependence on someone or some org external to the Scrum team").  You would handle this the same way as in Vanilla Scrum.  Here is a couple of techniques:

http://www.quietagilist.com/blog/2014/10/16/handling-external-dependencies-in-scrum  

I know it's an oft asked question, but how do Infrastructure project sit with the Agile/Scrum/Sprint concepts?

Start with the concepts of transparency, inspection, and adaptation.

- Is there transparency over work which is queued and ordered in a backlog? Is it clearly delineated from work in progress, and from work which is considered to be “Done”? Is there an agreed understanding of what “done” really means in this context?

- Is there a clear team with a membership boundary, where team members collaborate to complete work to the “done” standard? Is that team in a position to inspect the progress of work and its usefulness to consumers?

- Assuming that there is indeed a team which inspects its progress, do team members have the competency to adapt their way-of-working, and the work itself, to better fit needs and expectations?