Since you mention NTSC, I'm assuming you're in North America, and Spitz's SCART cable won't be that helpful... There are a few other options though:
- A genuine Commodore 1084S monitor with the proper RGB cable would be the most authentic solution... but 1084S's are pretty expensive these days. Alternatively, if you have an IBM PC CGA monitor or an RGB monitor meant for an Atari ST, those should be relatively easy to get working, though you might need a custom cable.
- If you have a multisync monitor, these simple VGA adapters would be a super cheap option... but VGA monitors capable of 15kHz sync are not common.
- An A520 adapter would give you a composite output, and they're not that expensive either. Should be good enough for games, but will be pretty bad for any Workbench or CLI usage.
- The Indivision ECS would provide a true VGA output that should work with any monitor. This is the most expensive option, but definitely the most modern as well.
You'll also need an Amiga mouse if you don't already have one. PC Serial mice are NOT compatible, though there are adapters for PS/2 or USB mice. Even if all the games you like are played with joystick, you'll often have to click the mouse button to get through crack intros and other stuff, so it's really not optional.
Getting software onto the Amiga will be a bit of a pain too, since you can't simply write Amiga floppies from a PC. The Amiga itself can read PC formatted disks, but even that will be somewhat rough. I'd recommend getting a Gotek drive and flashing the firmware, which basically lets you load ADF images off a USB flash drive. If you really enjoy all the Amiga fun you're having by this point, and you've got plenty of money to burn, you can also look into accelerators, memory expansion, and IDE interfaces for hard drives... but all that crap gets very expensive very fast. It's hard to recommend taking things to that kind of level when a $30 Raspberry Pi can do all the same tricks.
--Zero