There are no specific hardware requirements for the ADP besides having a Mac that runs a current version to support Xcode. Anyways, I know hardware and software are not entirely overlapping realms of knowledge but shouldn't you still have at least a basic grasp of it as a developer? The Mac Mini 2010 uses standard DDR3 SODIMMs (the kind that are used in laptops). If you buy some that are "too fast", they will just run at the fastest speed that your Mac Mini supports with no harm done. In any case, you are not the first person to face the dilema of upgrading the RAM in a 2010 Mac Mini, and if your have any doubts the answer is just a google search away. You have plenty of cash to get 8 GB of RAM and an SSD to breath some life into your Mac... so don't waste it by being daft.
What I was saying is in order to participate in the Apple IOS Beta's (like I am doing right now) I have to Register my Apple IOS Devices with the Apple IOS Developer Portal using Xcode. Otherwise, the IOS Beta' s will fail to install properly. Oh and by the way, Although I do NOT have a Developer Education, I do have an IT Background Education even though I am currently Unemployeed (I have a Certification in Computer Networking), however, the College that I attended mainly trained us on Windows 2000 Client and Server OS's. Just FYI.
I also have my own Website where I have set up a Word Press Blog that is Registered and Hosted by Godaddy.com. it' s at both kevinpanzke.com and kevinpanzke.co. Just FYI.