Gonna go with the Billion mate, they're tried and tested with the DSLAM's that UKO are using for ADSL2+ - I just wish I could get something that was as reliable as my old Efficient Networks 5861- ok it's not consumer grade hardware but that thing was an absolute rock!
Yeah a lot of kit uses the 2.4Ghz range as it's unlicensed if I remember correctly, video senders and the like can be fatal for 802.11b & g - a is better as the spectrum isn't as widely used but then again it can be harder to get that kit as pretty much everything supports 802.11b
I use Kismac to analyse the situation at home, the Windows version is Kismet - if you've got a supported card then you can get a lot of good info off that, then I use some Apple diagnostics software to monitor the db level on each channel, some are stronger than others and you reduce the risk of interference from other networks, it's a nightmare round here living on a new estate, I can see over 10 wireless networks some days!
