Curious as to why you would need one, you can put your spawn point anywhere you want with a bed. Even on top of the crypts.

The problem with looking for a swamp close to the starting point is that there is a default distance between starting spawn and the biomes.
This seed is pacman: tl8CMtFHNi
This one is a donut: vrvx2DPHVR
They're not good for anything though.

MA2KltNmxU
y7kzPGENpZ
Both have swamps to the north with a lot of crypts