I've never installed on anything shy of 80Gb, and the last time I specified partitions manually 4Gb of DDR2 was typical.
Laptop is i7 3517u, 8Gb DDR3, 128Gb Primary SSD, 32Gb mSATA.
mSATA is sitting idle, thinking to install Linux on it; probably Debian. How much swap though? Not planning on huge amounts of storage, media can go on the NTFS drive anyway. Just OS, LAMP server and probably a couple of development packages.