Some of this is parroting previous posts, so please forgive the repetition.
 
https://www.cpubenchmark.net/ is a good resource for looking at computer components if building a machine. This machine has never been reformatted/reimaged since I installed an SSD in it 3+ years ago now. I use this machine for everything under the sun, including high-end 3D gaming, am always connected to the internet, and install/uninstall programs often (I currently have 240 programs installed).
 
CPU-wise: Intel i7 Sandy/Ivy bridge models (ones with K at the end, e.g. i7-3770K) are more than sufficient for X3.
Graphics: X3 is not 3D-intensive, so a decent card will suffice (most cards do 2D more than adequately).
RAM: I initially got 8GB on this machine knowing I could upgrade if needed, and have never needed (ironic).
Interface: The 2in Focusrite models are very adequate for a solo performer who overdubs.
(I personally prefer desktops over laptops simply due to upgradability and ergonomics).
 
The only work that strains this machine is hard-core video editing (Adobe Premiere Pro), which can put heavy loads on both CPU and RAM, depending on what is being done. Anything audio related has not phased this machine (and my SSD and graphics card are overkill for DAW usage). But also take this with a grain of salt, as work flow plays into this as well (excessive plugins or CPU-intensive plugins can eat up CPU/RAM if not paid attention to).