Kludging a 9.5v 22w supply?

If you needed to come up with a 9.5 v 22w spare laptop power supply,
how would you do it?

a) Get a compact 9v output switcher and try to rework it for a
slightly higher output voltage?

b) Get a 12 volt unit and add a linear regulator with a big heatsink

c) Get a 12 volt unit and add an additional switching regulator? which
regulator?

This is incidentally for an Asus EeePC, which is an astoundingly
capable, affordable micro laptop that's too new to have any
aftermarket or even manufacturer accessories available. First
machine I've ever seen that's small enough to carry, cheap enough to
risk carrying, and capable of doing real work... ultraportable
terminal, compile code if you must, web browsing... and actually it's
just begging for a stack-under USB scope-a-lyzer add on.

Reportedly, 9 volts is not enough to convince it that an external
supply is present.

.