since I was prompted personally - here some thoughts:
Fundamentally, an up-to-date chipset and CPU (i5 or i7) should definitely do the job. Wouldn’t look at the “gaming” machines, since the $$$ you spend on them is often on graphics capabilities, which are mostly wasted on a Cantabile machine. I’ve had some success looking at “office”-specified laptops; you can get them refurbished at a good price (Lenovo Thinkpads!).
Processor-wise, I haven’t seen such a massive difference between i5 and i7 in my Cantabile use, so going with an i5 might be a way to save some bucks. I would look for a quad-core processor - multi-processor use doesn’t always help with audio loads - single-processor performance is still pretty relevant, so CPU frequency is definitely a factor, but I wouldn’t look at anything overclocked. The key for audio is reliability and stability, not the last 5% of performance…
Today, I would go for an all SSD (system on M2) machine, but you can get some pretty decent hybrid setups (SSD + HDD) that perform well. Depends if you use lots of sample-based instruments - then by all means go all SSD.
RAM: that’s where I’d spend money - especially if you use sample-based instruments. 16 GB is a good basic setup, with lots of samples, I’d go for 32 GB.
Re touchscreen: I use a touch monitor with my live cube, and it’s pretty useful for some tasks when using Cantabile live (quick selection of songs from the setlist grid or operating the control bar), but generally, I prefer controlling Cantabile from my controller keyboard via MIDI with buttons and pots. Touch screen operation is just too fiddly on-stage for my taste and absorbs too much focus - I want to concentrate on playing and singing…
In my case, I use the touch screen since I don’t have a USB keyboard sitting around during gigs (I use a mini-PC-type device, not a laptop, but I’m not missing ANYTHING when I use my live laptop that doesn’t have a touch screen.
Long story short: I personally wouldn’t spend money on a touch screen for a cantabile laptop - I’d rather have a good number of buttons, faders and dials on my controller keyboard.
There are tons of laptops with these specs, the problem is that not all of them are optimized for smooth real-time-audio operation. And you can’t decide from the specs if this machine will work nicely or throw tons of glitches at you - power management can be messy on laptops. So it’s really trial and error.
Lenovo Thinkpads have been a pretty solid choice; Dell is hit-or-miss (some praise them, others won’t touch them with a 10 foot pole); I have had a good experience with my Acer Nitro, bad experience with an HP gaming laptop that I couldn’t stop glitching, …
The best way would be to check out the laptop you are considering with optimized power settings and LatencyMon for some time - if there are funky interrupts, I’d stay away…
Hope this helps!