I like both System Three Quick Fair and ATC Poly-Fair.
Both are available in one day to your area from Mertons
www.mertons.com
The System Three Quick Fair is an epoxy based fairing compound that works great.Easy to apply,very durable and sands easily.
The Poly-Fair is a polyester product that is also easy to use and apply.It is like a very high quality version of body filler.
I guess I like the Quick Fair the best,although both are quality products,and either one would work well under Awlgrip.
QUICK FAIR
http://www.mertons.com/Epoxy/epoxy_r...quickfair.html
POLY-FAIR
http://www.mertons.com/Epoxy/polyest.../polyfair.html