No there's no such thing as a 'too big swap / boot'. What there is, is 'space that never gets used and could usefully be devoted to storing files'.
Seriously, a 2GB swap is waay over the top. If you're gonna be running a box with 1GB of RAM, the system is hardly ever gonna need to swap out. I'd say go with 256MB.
How many distro's are you gonna install on this box? 100MB will be room enough for several.