Well if you are using any of the aluminum shades EXCEPT for polished aluminum you can actually use any gloss enamel paint (black preferred) or according to the Alclad site, model primer sanded with a fine grit sandpaper or future... (I blinked when I saw that too... future!!!)
here's the site:
http://www.alclad2.com/application.html
be careful not to try to cover the model in one or two coats. when it gets too thick it can develop cracks in the finish even several weeks after painting... (I know because the drop tanks on my P-47 did
) go with very light coats until covered.
The only thing is on my first Alclad kit I used the alclad primer and it never felt dry. Even 3 weeks after spraying it felt sticky and if I left my finger for more than a second or two it had a foggy fingerprint that dissapeared after a few seconds.
But at the cost of the Alclad primer I would save it for the glossy aluminum and chrome and use one of the other suggestions! On the alclad site I posted there is a guide to spraying it so that might help...
Good luck and I look forward to pictures!