I own one of the Gateway NV53 series as well. I think that Win XP drivers were just never released period as the laptops were brought out long after XP was sold in retail channels (assuming you're not buying OEM from a mom and pop shop). You might be SOL. Granted Windows 7 is a very nice OS so I can't see why anyone would go back to XP especially when Windows 7 has the XP mode built right in
your idea about Win7 (windows XP Mode) is not applicable on all version
and Gateway NV53 series shipped with win7 home prem. and XP mode is not a part of it.