Tom Abrahamsson shoots it at 320 and develops ten minutes in D76 with gentle agitation (I believe 5 seconds every thirty, which is more than I would do... check out his Tri-X and D76 thread in his forum.) Elsewhere Chris Crawford, another rff member, discusses his own procedures and if you search around he's posted tons of stuff online (his website I believe) on film, developers, and scanning. He's particularly smart about scanning and post-processing. I'd search out those discussions. The point if you're scanning, I gather, is to hold down the contrast somewhat for purposes of better scans, then up the contrast again in post. Your lab sounds good: tell them the outcome you're after and see what they recommend. I shoot some at 320 and some at 400, all with the intention of developing in Xtol with precise timing and agitation, and sometimes I manage this, but mainly since I'm often so wildly behind in developing film (i must have forty rolls lying around right now) I end up doing a bunch of stuff, even unmatching stuff, stand developed in rodinal 1 hour with very minimal agitation at 30 minutes. I usually (but not always) like the results and you can't stupid-proof it any better than that.