Hey, want to apologise to those who had requested directions for the Fuji Hunt kit. I didn't check back on this thread 'til just now.
The 5-L kit is available at Process Supplies, even if it isn't listed on their site. (They have occasional items listed that are no longer in stock, and many items not listed that they actually carry. The best thing to do is ring them and they can tell you if they have something you want.)
You can reach them at:
13-25 Mount Pleasant, London, WC1X 0AR
Telephone: 020 7837 2179
I'd call them; I've not had much luck in getting replies to e-mails. But they're nice folks to chat with.