A listing with pricing of items available is at http://www.randomize.com/amigaproducts/a1200parts.html.
Randomize also offers a growing list products for your Towered A1200 with products and pricing available at http://www.randomize.com/amigaproducts/a1200towerparts.html.
Randomize, Inc. has the answer for your Amiga Systems needs. The Genesis Series is here. Check them out at http://www.randomize.com/genesis/