System requirement for Wireless Cardbus Adapter

I'm looking to purchase a wireless router and adapter card (802.11b) for an
older PII 266 laptop. I considered a D-Link 614+/650+ combo but the manual
specified a 300mhz minimum machine.

Similar Netgear combos say 400mhz minimum...

Linksys combos say 200mhz minimum...

SMC states no minimum processor requirement...

All specs are with a 32-bit Cardbus adapter. Is this requirement truly
specific to the hardware or does each company simply have different
standards for what they consider minimum? Wouldn't each adapter card require
the same system resources?

Has anyone set up a wireless network with a similar machine? Any opinions on
whether or not a PII 266 machine is capable of supporting this hardware?
Would a 16-bit PC Card adapter be less demanding in an older machine?

TIA,
David