re: FPGA, the Analog Pocket with an Everdrive also works great. I use it to play GB/GBC/GBA games on my TV via its dock. Sadly, those don't support sleep and stuff but that's worth it.
I never had a Game Boy, back in the day I was the kid tethered to the power cord with his Game Gear. I almost bought the adapter, but then I realized none of my games had saves so I had no reason to want to use the real carts.