Well, I don't think this is really a matter of conscious choice.

One uses the rules a setting is writtten for - ZGG BM was for d20, so our LFC started with d20.

In general, even though every grognard will fervently protest this, D&D games feel pretty much the same, regardless of what edition.

:) Yeah, I am that much of a help.

As to rulebooks, for any d20 game so far, my favorite additional tools are the Penumbra Fantasy Bestiary from Atlas Games, as well as Wizbro's "Heroes of Horror" and "Heroes of Battle".

Not so much directly an influence on the LFC, but a worthy pic nonetheless is the "Thieves World Players Manual" by Green Ronin.

- Oh, and of course, we use Players Handbook II extensively - all the knight characters in the game fit the class presented there.

While Blackmoor was running a living campaign it was in 3.5. There are various blackmoor books out there for 3.5. As far as races, the core book of blackmoor explains the varients of the core rulebooks races (i.e. Westryn and Cumasti elves, Thonian (human) and high thonian, peshwah (human), there is an alternate halfling as well, but can't think of the name of it right offhand. The new halfling race is much more combat focused (warrior is favored class).

Moved to the Rules Forum.