A laptop with an iGPU and loads of system RAM has the advantage of being able to use system ram in addition to VRAM to load models (assuming your gpu driver supports it, which most do afaik), so load up as much system RAM as you can. The downside is, the system RAM is less fast than dedicated GDDR5. These GPUs would be Radeon 890M and Intel Arc (previous generations are still decently good, if that's more affordable for you).
A laptop with a discrete GPU will not be able to load models as large directly to GPU, but with layer offloading and a quantized MoE model, you can still get quite fast performance with modern low-to-medium-sized models.
Do not get less than 32GB RAM for any machine, and max out the iGPU machine's RAM. Also try to get a bigass NVMe drive as you will likely be downloading a lot of big models, and should be using a VM with Docker containers, so all that adds up to steal away quite a bit of drive space.
Final thought: before you spend thousands on a machine, consider that there are at least a dozen companies that provide non-Anthropic/non-OpenAI models in the cloud, many of which are dirt cheap because of how fast and good open weights are now. Do the math before you purchase a machine; unless you are doing 24/7/365 inference, the cloud is fastly more cost effective.