Foam, where to buy?

I'd like to buy some of the high density foam that is used in pelican cases where I can make my own cut outs for some of my various speedlights and accessories. I plan on converting a 24" X 18" rolling suitcase for storage around the house and to have everything organized when I'm out shooting if I decide to bring everything along.

I'm did some searches on google, but I don't think I used the right terms.

http://www.lmgtfy.com/​?q=packing+foam

It's closed cell or otherwise foam. A quick search brought up this, just as one example (no affiliation):
http://www.foamforyou.​com/custom_foam_packag​ing.htm

Thanks for the quick replies.

I did something similar years back. After finding a suitably-sized Pelican Foam Set (either on Amazonor B&H): I used spray adhesive and a small carry-on piece of luggage to build a small/light hardcase for an underwater housing rig. Sure it's not as durable as the Pelican, but was much cheaper and effective too.