45 x 6581R4 SID chips for sale on Amibay.

http://www.amibay.com/showthread.php?t=30296

I just came across this sale while browsing, so I cannot vouch for the seller.

What I would do though, is register on the forum, and look at the users previous posts.

Or even ask on the thread if anyone bought from him in the past and the good were delivered.

Also might be worth trying to beat down his price of €25 + p+p each.

If enough of people ask for a more reasonable price, then they will most certainly get it.

BTW, that site is probably the best place at the moment to find SIDs for sale besides ebay.

Its also excellent for buying Commodore hardware.