If you're noise sensitive and power insensitive, then a linear
is the easy way out. At low currents and not much load
ripple / spike current you might not even need to have
off-chip decoupling.
Distributing smaller, local regulators around the chip may
give you better results than a single big boy, especially
if some blocks are "busy" you can keep their noise out of
the rest, provide each one only the capacitance it really
needs, etc.
How much current, is your #1 question. More than 100mA,
you have some hard thinking to do. Less, just do the linear.