AFAIK there's no difference between F1 and F2. while the system 16 website separates the games the MAME driver lists them all as "Taito F2"
https://github.com/mamedev/mame/blob/master/src/mame/drivers/taito_f2.cpp
I own several of the games on System16 F1 and F2 lists and can tell you the mobo is the same.
there are two variants, the long and short as oneleaf stated, but they're functionally identical.
a lot of these games also came as single board versions, essentially the mobo and game board rolled into one. I've started to collect the single board versions, since the mobos seem extremely difficult to track down. and they're a lot more compact.
And before anyone asks about conversion... it's really not all that viable. nearly every "ROM board" and single board version is unique.
There are a few games that use "very similar" PCBs but even those would require PCB modifications and additional chips to make a conversion work.
I've played around with trying to convert Football Champ to Dead Connection, I think it's possible but it requires some 74-series logic ICS and adding wires for extra address lines. without access to a real Dead Connection PCB to see how it differs in routing I couldn't get very far.
For this same reason I don't know that a Multi would really be viable on this platform either, there are a lot of different custom chips that are only used by one or two games each.
Can I buy those above rom boards, and just plug em in to the mother board and they'll work or do they need PALs or something?
yeah, if you wanted to you could just buy those ROM boards, plug them into the mobo on your Metal Black and go, nothing else special needs to be done.
if you have any other questions I own the following:
Ah Eikou no Koshien - ROM Board Version (x2)
Cameltry - EU Single Board version
Dino Rex - JP ROM Board Version
Euro Football Champ - EU Single Board Version
Growl - EU Single Board Version
Hat Trick Hero - JP ROM Board Version (x2)
Majestic 12 - JP ROM board Version
Majestic 12 - US Single Board Version
Mega Blast - JP ROM board Version
3x Long Mobos
3x Short Mobos
I get the impression that most JP releases were the ROM board/Mobo combo and most International releases were Single board versions. At least my own collection seems split along those lines.