A Computer for Sir Terry

Sir Terry Pratchett, Order of the British Empire, is a very prolific writer, most famous for his Discworld series of books. He is known for a major use of computers and the Internet, and yet has said in an interview that his favorite computer of all time was the first one he owned, the ZX Spectrum. That computer also proved insufficient for modern works, as the same interview reported that his novels exceed 10 MB by the time of their completion, and the ZX Spectrum had only 64k of memory and recorded to tapes, a slow and sequential process.
Hobby groups exist that recreate old computers, and if Sir Pratchett requested, I would ask one of them to make a portable computer with the features of the ZX Spectrum, like its rubber chiclet keyboard, and write software with a similar interface. We would need at least a word-processing program and an Internet browser. I would ask that it have at least 100MB of RAM, a framebuffer (with more RAM, the Spectrum supported a 256×192 color display, and I would want better than that), RF Video, and wireless network access. It will also need Z80 emulation if it isn't using a Z80 type processor (do they even make those anymore?), and NFS (Network File System, a means of storing files on a separate computer that it reaches with a network). The reason for these will become apparent in the next component.
I would then provide Mr. Pratchett's home with a wireless network, and an immense server with RAID 10. The RAID would be shared with NFS, and here is where the Spectrum clone's OS and programs would be stored. It would have room for terrabytes of data for Sir Pratchett to use, and would provide the Internet connection. The RAID setup would ensure both a metric insane supply of space, plus reliability in case of the loss of any of the drives. Ideally, the drives would be setup for hot swapping, to minimize issues for the end user.
One major obstacle I have this this is my unfamiliarity with the ZX Spectrum, which was not sold in the United States where I live. Pictures of it suggest that it was portable and battery-powered, broadcasting video to a television set. Articles describe it as receiving its programming from audio cassette, yet only some models have a visible tape player, leaving me wondering how the other models received programs. (burnt permanently to a ROM, perhaps?) The design would be much simpler if wired connections could be involved, since electrical power can be received via socket, wired Internet is faster and more reliable than wireless, as well as more difficult to snoop from the outside. And video to the television almost assuredly works better if we can send it by a wire, instead of having to broadcast it. I would want the device to resemble the Spectrum in physical size, and operate similarly to one only better, since it could view the Internet, which the average person couldn't in 1982, edit entire novels, and save to the massive server instead of a gazillion tape cassettes. I have literally no idea how the ZX's OS operated, and so can't help with the programming.
I would encourage the creators of the Spectrum clone to license the design with Sinclair Research Ltd, the company that invented the Spectrum, and sell it together. I could probably be convinced to buy one.
Sir Pratchett, however, would probably prefer that people donate towards Alzheimer's research, as he was diagnosed with the disease in 2007, and has noted with quite a lot of alarm that research into the cause and treatment of the disease has been somewhat lacking.