A bit of a late reply but for reticulated foam i had previously bought mine from a seller on ebay but when i tried to get 1/2 inch foam the next time they didn't do it any more.
I used the foam shop and the only problem was the thinnest they do in sheet foam is 2.25cm. However they were great to deal with, the prices were reasonable and due to an error at their end (which they were quick to sort out) they even added extra foam to the order for no extra cost. Also i found that if i cut out the pieces of the pattern on the thicker foam using a very large and sharp knife i can cut it pretty much in half without too much deviation and get the 1/2 inch thickness anyway or for some puppets the inch works just as well.
For Antron I have used Mermibridg and I also bought some more recently from
http://www.outoftheboxpuppets.com/ Although it shipped from the US they often have some brilliantly priced remnants/soiled fleece (although i bought one that was 90% useable and couldn't actually find marks on it anywhere other than the back of the fabric). If you can afford to bulk buy some decent sized remnants and I always throw in a few dome eyes and other small bits while i can, then you can get a lot for a reasonable amount.