[Ravq]

There are a few sway bars offered for the Maxima. Here are a couple of ways to tighten the suspension:
http://www.maxima.org/shoptalk/sub_m...sb/index.shtml
http://integra.vtec.net/geeser/megamax/bars.html

Check out the Maxima.org forums for opinions and reviews of the different brands.

And here are some links for additional information:
http://www.cattman.com
http://www.stillen.com
http://www.5thgenmaximas.com/index2.html
http://www.maxima.org

Also springs and shocks/struts are a major factor in suspension feel. Getting stiffer springs and aftermarket shocks will dramatically improve handling. And as for the auto to manual swap, I've heard of a 4th gen having accomplished it so I would assume it's just as easy for the 5th gen. See here: http://www.stormpages.com/autoto5spd