a) you have to search for Dell&Co if you want a laptop
b) new ATX-mobos come out on a biweekly basis even if you stick with just one brand
c) good luck in finding such a mobo new when MorphOS-support is actually done (atleast 6 month after initial release of that mobo)
d) even more good luck in finding that exact mobo 2nd hand with all those confusing model-numbers (which might not even be enough to identify the exact model)
All unlaid eggs, but IMO unless they find a way to support a wide range of HW shortly after the release of that HW !without" falling into the AROS-driver-hell, 1-2 year old Apple PCs don't sound so bad.