Fast ram is always better (faster, you remember?) than chip ram - unless you need the chip ram for storing gfx or sound data - depends on what you're up to.
If you just have mechanical problems with fitting the fast ram board: locate an empty CPU socket (or more, as required) and use that to raise the Spirit board above the chip ram board. You might need to remove the metal shield and/or be unable to close the standard case though....
Another option is to add a standard 512 KB board. Depending on the original Agnus, the board configures as additional chip ram or 'slow' ram. If the (probable) latter is the case you can upgrade with a 1 Meg ECS Agnus (changing two board jumpers will be required) to get 1 MB chip without requiring additional space.
