HP Omen 25L vs Lenovo Legion T5 vs custom build

Hi,

My first post here and apologies for English - Please feel free to reply in Swedish as I can read quite OK (with help!).
I'm looking to buy a computer for work (mostly for software development), but being able to play some game would be nice (not that I have time). I am using a Surface Book 3 from the company and fairly disappointed with the CPU/throttling issues.

My budge is 12-14k without CPU, keyboard, mouse or speakers.
I'm looking at this
https://store.hp.com/SwedenStore/Merch/Product.aspx?id=494L4E...

Windows 10 Home 64
AMD Ryzen™ 5 5600X (3,7 GHz basklockfrekvens, upp till 4,6 GHz max. boostklockfrekvens, 32 MB L3-cache, 6 kärnor)
NVIDIA® GeForce RTX™ 3060 (12 GB GDDR6 dedikerat)
512 GB WD Black PCIe® NVMe™ TLC M.2 SSD
HyperX® 16 GB DDR4-3200 SDRAM (2 x 8 GB)
DTS:X® Ultra, (2x2) och Bluetooth® 5

and
https://www.netonnet.se/art/gaming/gamingdator/stationar-gami...

AMD Ryzen 7 3700 processor
512 GB SSD & 16 GB RAM
NVIDIA® GeForce® RTX 3060 Ti 8 GB
Legion Coldfront 2.0
USB 3.2 Gen 1, DisplayPort, HDMI

What would be better in term of thermal and upgradability. Or should I go with a custom built one? If yes, which configuration should I choose for the best bang of the buck?

Thank you!

Just want to report back that I went with a custom build
Ryzen 5 5600x
Asus Rog Strix B550-F wifi
Corsair Vengeance 2x8GB 3200CL16
Fractal Design Meshify C
Corsair RM750x
Zotac 710 (yeah I don't need gaming atm)
I haven't decide on SSD yet so I will be using my Samsung T7 Touch at the moment

currently cost 7-8k SEK which is quite OK for me. Plan to upgrade to CPU cooler as soon as I decide which one, RAM to 32GB, and yes a Graphic card when the price is more reasonable.

Thanks for the help.