I'm well aware that I'm asking an impossible question.  If someone were to ask me this question I would definitely answer with "it depends" on a nice day and potentially something snarkier on a bad one.

Still, here goes...

I've been working in my position as Library Systems Administrator for nearly a year at a small one campus college (our Sierra ILS shows roughly 100,000 patrons in a 14GB database).  My colleague who is a Systems Librarian and I have been trying to get IT to give us a Web Server to do sandbox testing and internal processing tasks.  Well be careful what you wish for...  Now we have been told that we have been granted this wish and we need to spec it.  Well usually in order to spec a server you need to know what applications you want to run on it.  Guidance from our Director is to neither be too greedy nor too skimpy.  We anticipate this environment lasting us 5 years.

We plan to install a LAPP or LAMP stack on it.  (maybe both databases?)  I don't see this as being a very heavy transaction oriented environment.  Some thoughts of things we would like to do with it:
run some customized ebook linkchecking scripts
schedule queries to get data from our ILS to a local database to keep more history and merge with other datasets from various sources.
Install websites for callbacks for SUSHI and REST APIs
??? the future ???

A bit of note on our background.  My colleague has a Computer Science Degree and I have a Computer Systems Diploma, but the reality is that we are not full fledged developers.  When I got my diploma, we programmed in C, (not C++ - that wasn't a thing yet).  I've got some recent experience with JavaScript and have been teaching myself Python just using my Windows PC and I'm having a lot of fun with it, but I still have lots to learn.

This will likely be a virtual server, so it won't be written in stone, but I'm still unclear on how much to ask for in terms of CPU, Memory and RAM.
Any tips, pointers, gotchas?  Things you wish you'd ask for when setting up your own test development server?

Thanks so much for any feedback!