The Borders are a bit of a desert wrt abattoirs. Your nearest is probably Shotts, just off the M8 half-way to Glasgow. You could speak to your local buitcher and ask who transports his pig carcasses for him, and bring them back to their premises. S/He would then cut them up for you probably was well. You would have to pay for the transport back from the abattoir, and when we did it it was charged at per kilo rate... it didn't work out cheaply. You can also book them into Shotts as a private kill (they used to do pigs in a Monday morning, but it's been a while since we had pigs), and get them processed by the butcher in Wishaw. That's what we used to do, the only disadvantage is you have to make the journey twice, but it could well be cheaper than using a transporter.
We have never attempted to do pigs at home, mainly because the problems with getting the hairs off, as well as having the means to hang the carcass so you can empty the entrails (our tractor doesn't have a front loader). You would also need a few helpers to move and cut up the carcass.
I don't know if there is still an abattoir north of Newcastle, there used to be one. May be shorter drive.