You SHOULD be able to share any connection that you have, be it AOL or any other using MOST wireless routers. The thing that MAY prevent this is whether the ISP demands the Mac addresses of the machines using the connection and if so, whether they will block more than one machine on the same connection.
However, there is a solution. You identify Linksys as a possibility and I would reccomend them to you. I have set up my own network using a Linksys WRT54G (On Nildram). Although Nildram dont watch your Mac addresses the Linksys has the capability to "Spoof Mac Addresses" which basically me4ans that any connected computer would appear to have the "Authorised" MAC address and therefore work.
The reson they do this is to prevent you getting together with your neighbors and sharing a connection whilst paying only one fee.
Another network I set up for a friend has who has NTL had just this problem and we had to spoof the addresses for three more computers - no problems at all.
Whatever the situation with the Mac addresses all (telephone) broadband signals are the same and the equipment that you use to receive them will work regardless of which ISP you are with. Most ISP's will have a "reccomended" router that they will offer you, normally because they have a large discount from the manufacturer and tend not to think that Jo Bloggs in the street knows about such retailers as Ebuyer or Dabs etc. Have a look on the net for their recomended router and see the difference in price!
Hope that helps.