HP tower PC with Intel Core i7-2600 @ 3.40GHz CPU, 12GB RAM and a 1TB HDD, tested with Kubuntu.
No keyboard or display, although I have a 24" display available, if you chose to use that you will need to get cables and a stand for it. I also tested with an 2.5" SATA SDD and the performance is significantly better so with a £25 investment you can have a working PC for some years.
Due to licensing restrictions no Windows available.
HP PC Tower (Bramley Corner RG26)
This offer has been gifted to someone and is no longer available.