You're probably not going to find a direct equivalent.
FCEUX's addresses are confusing because NES addressing is confusing. To really understand them, you just have to understand some NES memory basics. To make matters even more complicated, how memory works can vary from game to game.
Here's what you need to know for FF2:
NES ROMs start with a 0x10 byte header.
After that there are a series of "banks" of PRG-ROM, each bank being 0x4000 bytes (16K) in size. So the ROM looks like this:
0x00000 - 0x0000F = Header
0x00010 - 0x0400F = PRG bank 0
0x04010 - 0x0800F = PRG bank 1
0x08010 - 0x0C00F = PRG bank 2
0x0C010 - 0x1000F = PRG bank 3
0x10010 - 0x1400F = PRG bank 4
0x14010 - 0x1800F = PRG bank 5
0x3C010 - 0x4000F = PRG bank F
FF2 has 2 "slots" in memory:
$8000-BFFF = can have any one bank swapped in at any time
$C000-FFFF = always has bank F swapped in.
This means that when you are looking at 'NES Memory' in FCEUX, the $C000-FFFF range will always match offset 0x3C010-0x4000F in the ROM.
However, the $8000-BFFF range in NES Memory will often change between a different 16K bank of ROM as the game swaps in difference blocks as they are needed. In FCEUX, if you are in 'NES Memory' view in the hex editor, you can right-click on a byte in that range and say "Go here in ROM file" and it'll switch to ROM view telling you the exact file offset.
All of that said... what I usuaully do is create a full disassembly of the game (just using a naive disassembler, like 6502d). You'll get a lot of garbage, but it's good enough for a reference. Then use that to jot down notes and read/follow code while using FCEUX to step through it.