Hi, I guess it all depends on your usage. Technically, on wattage, you would add up all the ratings of the devices you intend to connect to be sure your computer can supply. Without knowing that, nobody can comment.
Similarly, without knowing what your greatest ram usage project might use, it’s not possible to make a recommendation. If you look at the Task Manager while your most memory intensive project is running in Cubase, that should probably give you an idea. Nevertheless, more RAM is more future-proof. But, as long as you have a slot, you can always add later.
Concerning SSD, by all means, get the biggest. This one is the easiest! But you should have a second drive as well.
About chip, I think it is still true that many apps or parts of apps (plugins for example) are not able to make use of multiple threads, and therefore, the chip with the highest clock speed is the best, and the clock speed is more important than the number of cores. Maybe somebody who knows more should comment.
One last point, without knowing the specs of the Surface, I guess just about any desktop computer will have major advantages. And you probably ought to have a fast graphics processor. In principle, Cubase doesn’t need a fast graphics processor, but post after post on Gearslutz says that upgrading the graphics processor is the single most potent performance improvement to Cubase. I can’t explain it, but I think it’s true.
Looking at sites recommending music production computers, they’re all settling on gaming computers, which always feature fast processors, fast graphics processors, ample main memory, and an SSD c drive big enough to hold all the programs, combined with a big spinning hard drive for projects and sample libraries.
