So full disclosure I'm not planning on building a fixie I really want to build up a frame with a Sturmey Archer 3 speed... However, you guys are the best at setting/figuring out chainlines etc. So I have a couple of questions to start (been researching and reading for days but I don't know much).

1) Which Frame should I pick?

I Have two to choose from. Either a Schwinn 1988 giant made world sport (I assume this based on Serial of G1118 and head tube stamp of 3338)

OR

Some super weird late 70's/early 80's Sanki (Can't find much on this thing, appears to be some sort of japan import).

They are the same size and about the same condition/weight. I'm leaning towards the Schwinn because I fear the Sanki could have some weird threads etc. Also the sanki appears to have a crimp on rear dropout but the Schwinn is welded on.

2) What do people commonly use for the front chainring/bb? Any easy resource for what I should buy or should I just drop/remove the inside chain ring and try to adjust to fit it to a line that would work with my Sturmey 3 speed? I did some quick measurements and from what I can tell the spacing between my rear dropouts is about 120mm. The center offset (from center of seat tube to outer chainring) is 47mm.

I'm sort of worried that I only about 13mm from the inside arm to the gear. Is that too tight or did I screw up my calculations?

I plan to build the rear wheel so I can dish it as needed (well I'm going to try... lol)