In the Market for a Custom Flashcart / Mod

[Jedi Master Baiter]

So I've nearly given up hope of acquiring a TNS-HFC5 flashcart: http://www2s.biglobe.ne.jp/~tns/nr26740601.html (unless someone wants to sell me one?)

All I need it for is playing back NSFs using real hardware expansion sounds (not emulated, like the PowerPak and EverDrive do). Would it be feasible to mod the EverDrive to use onboard expansion chips (VRC6/VRC7/N163/S5b)? Or add a dongle to plug in carts that have these expansions?

I don't need it to play games, just music.