Frugal wireless config, possible?

Hi Everyone,

Been sticking to wired networking for the longest time and have had the phobia of going wireless even though there has been advancements in terms of security. However i now need to go into this as i need to set up a mini office on the other side of the place where my current wired network is.

I have been waiting out the whole battle between the different A-B-G standards and was wondering if any of you guys have thoughts/experience/advice on this idea of mine:

Due to the G+, SuperG, Turbo-G/speedbooster and WiMax formats coming, i was hoping that I could set up one of my old PCs in my wired network, to act as a access point, by plugging in a PCI wireless access card, instead of buying a specific standard's router. Thereby transmitting the wireless frequency to the remote location with another old PC with another wireless access card, and from there, plugging in one of my extra wired routers to feed to my network cluster there.

I got the idea from this:
http://www.tomsnetworking.com/...n [...] -page1.php

I am thinking that this would be a good idea and gives me the choice of going for better formats in the future, instead of investing in a wireless router now.

Also, I'm a noob at this bit, I would like to have a network share between my PCs. With the wired network i was already paranoid enough. Now if I have to go wireless, how should my network shares work? Wouldn't anyone that connects to my network have instant access to everything?

Looking forward to hearing from you guys.