flaky linksys wireless

My remote computer is connected to a Linksys WRK54G router by a WUSB54GC
adapter. When I first installed Vista and set up the wireless network, it
was pretty stable. Windows update offered a driver update which I applied.
Since then it's been stable, losing connection every other day or so.

I rolled back the driver but it hasn't improved dramatically. I just
downloaded and installed driver version 3.0.1.0 from the Linksys web site. I
haven't assessed it's stability yet, but does anyone have any experience
with making this particular connection work?

The layout of my house and use of 2.4GHz wireless phones sometimes causes
interference. I don't plan to buy a new set of 5.8GHz phones but do plan to
upgrade the 802.11 setup to N. Unfortunately, all I can find on the market
is 'draft', despite N reportedly having been ratified. I don't want to buy
non-compliant hardware without assurances it can be upgraded by firmware,
but I can't find anything in writing supporting that.

Can someone recommend for or against proceeding with an upgrade to N? I'm
talking about consumer-class hardware, not very expensive stuff. If I could
get one that supports use of a subnet other than .1, that would be nice. If
so, I can open my older WAP on 192.168.1 for public use by visitors, without
exposing my family's 192.168.x subnet.

Thanks in advance.