Find the Super Potato in Ikebukuro. It's a bit smaller, but is slightly cheaper than the one in Akihabara. Also it's right near a red light district, where I saw a sign for "Cherry Sexual Assault Service."
The AV cable from either a N64 or Gamecube will be enough to connect to the RCA connectors on a TV (the red, white and yellow sockets.) As for the power supply, the NHS and SNES apparently have the same power requirements, as I'm using my old NES power supply just fine.
As for games, short of going to Japan yourself eBay is your best bet. Off the top of my head games 3 to 5 in the Great Battle series are good, The Firemen is a fantastic but shortish game... Aside from that I just picked up anything that looked interesting that I was also sure wasn't an RPG.
I have major anxiety issues which lead to depressive episodes, so it's best to head those off when I can. To wit, I have installed a bunch of Skyrim survival mods as recommended by RPS and plan to just get lost in that world whenever I'm feeling on edge.