I'm replacing my old laptop which has intel i9-9880H 2.3ghz chip 64GB memory and two 1TB drives. Would like to increase to 1TB and one 2TB drive. Part of an upgrade from windows 10 and a faster cpu.
It depends on your criteria for budget, size, weight and GPU needs, not so much CPU where there are fewer good choices. The current iNtel Arrow Lake is in U, H , and HX versions, though the U is really for lower end, low power usage and not the newer architecture. There are also V series CPUs with a better NPU, sacrificing CPU performance.
Most likely your old laptop was rather large and so the HX series from 255HX through 285HX would be a good choice. Those all have 8 P cores differing mostly in speed differences that are primarily power/heat limited so the particular laptop is more important.
I'm not sure what kind of discrete video card that unit had if any. If you need to do heavy AI image processing in the field then you will want a discrete nVidia GPS from the mobile 4000 or 5000 series, most probably in a relatively expensive gaming laptop.
Multiple SSD slots are not uncommon in the larger laptops, though the sizes vary. 2280 is the traditional M.2 size, but there are more small SSDs like 2242 or lately 2230 due to the proliferation of the handheld gaming devices. Generally it's cheaper and better to get a minimal SSD and add another one yourself. SSDs with larger capacities, TLC and/or DRAM are hard to find or not available in the shorter form factors if that matters to you.
I don't know if it can be extended to 1tb + 2tb SSDs though. It is Intel Series 9 with 32 gb RAM and no video card, so probably would suffer for photo/video editing.
That said this is a $1k (on sale) computer, so prices go way up.
That laptop has one slot form what the specs show. The CPU is a refreshed version of the the Raptor Lake architecture, which is older than the current Arrow Lake. I think the IGP is also worse, but have not looked into it. If you want to do AI image processing with reasonable performance you need a discrete GPU which will drive the cost in the $2000+ range.
I have a different strategy than the normal person. I only use a laptop for storage and basic image reviews, not serious image processing and I want one 2.2-2.5 lbs. Since I'm hauling around 500/4s, 600/4s, etc. I'm fine with a 255H or 265H in the lightweight laptops so long as it supports 16TB of internal SSDs. For reference the IGP (ARC 140T) in the Arrow Lake mobile takes nearly a minute in DXO to process an image (RAW to 16-bit TIF DP XD/XD2) that takes 3 seconds on the desktop system, and that's not the fastest GPU. A WAG would be in the 5-10 second range with a mobile 5070 Ti or 5080. I'm sure you can find some actual benchmarks online.
I have an older Dell XPS, and part of my criteria was user-upgradable RAM and support for 2 NVMe drives. I'd have to check and see which models (if any) still offer this, but it would be high on my list. I'm now running 64 GB of RAM and have added a 2TB drive to the 512 GB that came with the machine.