RAID0 only works with two disks that must be the same size, and be attached to the same RAID controller that often requires the two disks to be almost identical models, if I recall correctly.
You could run them in JBOD mode (just-a-bunch-of-disks), but I'm not sure if Windows itself supports that - it is a feature you can enable for some external drives like WD's if you have their drivers installed though.
It's okay to have different models of drive, only thing affected is the IO speed but thats about it. Valid point on same size, would work if it isn't just that space will be wasted. Storage Spaces would work for > Windows 10, JBOD isn't needed.
These days using RAID controller is optional. Many motherboard these days provide RAID support on software level, which AFAIK have inferior performance and occasionally unstable.
I think the reliability got better for motherboard RAID so it isn't that big of an issue. IRST does help with it on Intel chipsets.