That song is available:
http://chronofan.com/Zeality/MNSG.zipThe songs of the dungeons in that game were divided up into three parts. The second part is probably "smoothest" for an introduction like this. (It starts at 0:58.)
Or maybe part of the third part is...well, take your pick.
I'd show Peach Mountain Shoguns first as Ramsus described, then Kajar Laboratories, then CE. Start the CE music with its logo.
Last Edit: If you want to check out other MNSG / GGA music, hit
http://www.hcs64.com/usf/ USF Central. Goemon games had great soundtracks. One of the greatest pieces of VGM ever composed is GGA's Creep Village / Without Relying on the Map, which you can sample right way in the music section of
http://en.wikipedia.org/wiki/Goemon%27s_Great_Adventure . For reference, we are borrowing the Peach Mountain Shoguns / Spring Breeze Dancin' thing from these games. The "Well, that's it for us. They should have called it Guardia NPCs #1, #15," etc. comes from that in CE.