the xicon polystyrene caps at mouser will be fine:
http://www.mouser.com/ProductDetail/Xicon/23PS182/?qs=sGAEpiMZZMsh%252b1woXyUXj2Wk4Z3nZoF90BVWr6rvbXU%3d
http://www.mouser.com/ProductDetail/Xicon/23PW310/?qs=sGAEpiMZZMsh%252b1woXyUXj2XVQGjeabU77qlb6tKBp2s%3d
I'll be sourcing mine shortly so keep in touch
*edit
Actually, those 10 nF xicon are HUGE (10mm diameter)
Check these out:
http://www.newark.com/lcr-components/fscex-10000pf-1-63v/capacitor-polystyrene-0-01uf-63v/dp/97K0250
Those are used on the oakley TM3030,are 1%, and VERY nice (glad I got a bunch of the radial ones when I built mine, i'll definitely try them in the VCF)
One cool thing abut shopping at Newark is that their UK division is Farnell so anything that Farnell carries that isn't available in the US you can order through Newark and have it shipped for a $20 flat fee which is not too bad if you load up on stuff that we cant get domestically