Does either one come with an original rigid fork? If so, go with the one that does!
I had a 'too big' 1992 Trek 990 (lugged, the first tig frames were '94) , and I've got a couple of later Singletracks out in the garage, including a '98 930 and a '96 990. The 930 has the wishbone type stay arrangement. This frame is a bit heavier than it's mid-90s upper end cousins (the 970 and 990, essentially the same frame). Between the two, I would consider the fork, the condition, the paint preference, and the price. I don't think you could go wrong either way, even though the love affair on this particular sub-forum is going to be w/ the lugs. Its a tossup between two great, American-built mtbs, so you can't go wrong.
Honestly, if they are cheap enough, just get both, ride 'em both around long enough and one will speak to you, then sell the other one, maybe for a tad less, for the cost of the added handpick consultation, then there will be no doubt in your mind you made the right choice.
EDIT: dug up an old thread that had one of my posts in it regarding the Trek 930, and here is what I wrote:
'here is what a 1998 Trek 930 OX II triple butted 18" frame weighs: 5.24lbs/2370gms'
I think OX-II is actually just double butted, but alas. I weighed my bare Trek 990 frame (1996, OX-III) in 16" and it was 2077g, about 300g lighter than the Trek 930 frame, although sizes were slightly different. I don't know what the lugged Trek would come in at, but after reading a bit near the end of the Trek Multitrack thread in the hybrid forum, it sounds like the weights between both the lugged and the tigged frames are pretty comparable.
Also, here is a GREAT thread all about the Trek 9xx series of mtbs -
https://www.mtbr.com/threads/mid-to-...81873/#replies