Hi
My dear wife is currently on a year long study course working from home and needs our pc almost full time. This means my "unimportant" photo processing is being left out.
My suggestion is to buy a laptop that I can run GIMP on but I've never owned a laptop (although I do have a couple of Android tablets).
So can anyone recommend a laptop spec to run GIMP on? The variety in prices is quite scary. I've also looked at the Surface Pro.

Many thanks in advance.

Any normal, modern laptop should run Gimp no problem, the size of your graphics will determine your hardware requirements. Since you have tablets available, I wouldn't even consider a Surface Pro. For the same money you can buy a much more capable laptop, (Core i5 or i7 Processor, 4 GB+ RAM, 500 GB+ HD, 512 MB+ Video Memory). Connectivity on a laptop is important, the more ways the merrier.

FYI, When I use my laptop at home it's on a regular monitor as main (dual screen, laptop on the side), using a separate full keyboard and mouse.

I have a 4GB RAM, i5 intel core, 500GB HD, 32 bit Toshiba laptop and it is fine with gimp and photo processing.
You may want to consider 64 bit though if you intend on any large graphics and most programs are made for 64 bit now.
A few people use wacom tablets for their gimp program too. Haven't heard of any Android ones yet.

I have a 6 RAM, i3 intel core 500GB HD 64 bit HP laptop and it runs gimp just fine.

I run GIMP on a touchscreen Dell Inspiron 15Z ultrabook, 8gb ram (upgraded from 6), core i5, 500gb HD/32gb SSD cache, running Windows 10. I haven't had any problems, and the touchscreen is very cool to use with a stylus. You can get the touchscreen model on Ebay for $300-350, the non-touchscreen model runs about $200. The i7 models cost a little more. I've never been happier with a Dell laptop, and I've had quite a few.