wireless networks

hey

i just got a job to implement a wireless network in a small coffe shop. The coffee shop is the size of an average 1'st floor of a bunglow house. Basically the owner wants to provide wireless internet capabilities for customers as there is a big demand. Basically any customer who comes into the coffe shop should be able to access the web through there laptop or palm or whatever.

So what i need is this.

what device do you recomend i mean what router. Now i looke at a linkysys WAP55AG.

Now do i even need to get a router with all the band capabilities. I wanted to add the Band A capabilities because i thought once in a while if someone comes in with a Wireless A adapter their internet will work too. or do i just need a normal wireless router.
now why would i even need to get an band A. As far as i know that would only matter if they are transfering files over the network. Which they will not be doing.


and if i have a wireless G router that means the wireless B network adaptor will work with it and so will the G but would the A work or i need to get a router with that capability.



this is what i have been pondering in my mind lately.

and also please tell me how much should this job be worth.
I am pretty good with this so its not like i go their and start reading instructions so don't tell me a beginner price or somethng. Give me a price that is not too cheap and something a professional company would charge as i take my job seriously so i do dress up.

Thanks a Lot


gaurav