best expansion port add ons for MM3 chip modded PS1?

[+Swami]

Oh, the PS1... Classic Gaming or Modern Gaming? Anyhow:

 

So, I've had a 9001 Ps1 for a long time. No mods, no expansion port. Just got a 5501 PS1 with MM3 installed for backups and imports.

 

What are the best plug and use expansion port accessories to buy, besides ODE like the PSIO that require further mods and lots of $$$?

 

There are ones for GB/GBC carts, various game sharks and some combination ones. Ones that allow for imports/backups would be redundant now. Are these good alternatives to rare, expensive GB/GBC/GBA adapters like the Super Retro Advance for SNES? I've heard the GB/GBC adapters for PS1 have no audio.

[DragonGrafx-16]

The Game Boy addon has no sound so no it's not a good alternative to play Game Boy games on the TV.