For "internet access" it won't make the slightest difference. With broadband connections running at the relatively slow speed of up to about 2Mbps, even 802.11b at 11Mbps is well above that speed.
Where the speed would be significant is if you are likely to do much file transferring between computers.
Also, depending on locations, it isn't always necessary to connect *all* of the networked computers "wirelessly". Any that are permanently located close to the router can be connected by conventional ethernet cables.