Oh yeah I won't be terminating it myself I'm just running the cable putting all the plug sockets etc etc on the wall and getting an electrician to come around as in my brother-in-law to wire it terminate it hook it all up and test it, absolutely no chance I would give this a go myself lol+1 for TLC Direct. They'll cut SWA to length for you - £6.62 per m or £300 for 50m. They also have a useful voltage drop calculator on their website.
Terminating SWA is a PITA though, without the right tools. YT has some good videos.
If you're doing anything of complexity I'd get a friendly sparks in. They'll have all the testing gubbins and will sign off the work with building regs. If you think you need 10mm SWA it's probably a new circuit and therefore notifiable work.