SSD Upgrade: 60GB enough? And cheaper optibay?

Hey guys i'm looking to do the SSD upgrade to an OCZ Vertex 3 series, but right now i'm caught between either getting a 60GB or a 120GB i'm not sure if a 60 will be enough for my user and program data. The 2 major programs on my computer right now are Maschine and Traktor Scratch Pro 2. I'm just concerned with bloating my SSD and having to constantly transfer files to 500GB optibay drive.

For those of you who have done the upgrade what have you found to be a good size and also can anyone recommend something cheaper than optibay? I saw some stuff on ebay but i'm hesitant to buy some cheap universal version.

windows or osx?

Os X

For SOLELY programs, _maybe_... but if you're doing production work on there too I would recommend the bigger drive for sure. You're losing a lot of the benefits of having the solid state if you are having Maschine access files for production off of a different HDD - namely that Maschine will load more quickly and may run slightly faster, but if you're accessing your samples from your other HDD you're not going to do so any more quickly.