If it is just for producing written work (ie essays) then any laptop is fine as long as it has some word based program. Mine have used iPads with keyboards initially but it is more complicated to download/ print in a school setting where everything is generally just dumped on a memory stick.
You will need to discuss with school their policies on accessing wifi - and also some insist that memory sticks used on school computers can't be used on home computers and the. Brought back into school (virus protection stuff).
Most schools have kids who uses laptops though (some secondaries have school laptops held within the learning support centre that can be signed out for classes by specific pupils for specific lessons).
I am assuming that he doesn't require any of the more specialist recording devices available (these are usually more useful for kids with other SN) but if you are curious, then each LA usually has someone either on staff or a local OT who can provide specialist equipment advice. There are a few different recording keyboards etc available. (Mine tried a couple but have gone back to standard off the shelf laptops).
Really just chat with the senco and ask how the process will work for downloading and handing in assignments.
I supported a couple of teens who had recording issues. At first I used to scribe for them, but in all honesty it was not an effective support. Once I arranged laptops so that they could record their own notes, they were much more engaged with the classes and better able to take in information and recall it. That doesn't work for everyone of course, but for these guys it was far more effective. Did myself out of a job, really, but the teens were much more independent and likely to achieve success in their own right.
Some teachers are happy to email their teaching notes to students with recording issues, some not. Again, just ask the senco what the process is in your particular school.