Here is my old Peter Wright anvil. It's about 140lb and would be an ideal size for a bladesmith.
The little anvil on top is a 431 LB Kirkstall wheelwrights/springmakers anvil. Don't know how heavy the larger one is.
The large anvil is not designed to be used on a stand, it was meant to be used on the floor by a team of strikers in the days before powerhammers were common.
For knifemakers who do not need to break down large stock I'd suggest an anvil weight of between 100Lbs and 250lbs.