Also, just had a look on the old forums and uncovered these tidbits..
Code13
According to the Calxis Sector Encyclopedia on the Dark Heresy site, Lycosidae is home to a/the Legio Venator Fortress. (Titan Legion)
NerdKing
+ from the published material so far (and the official word on the old BI forum) the only Astartes presence in the sector is the abandoned Templars base and two Iron Hands dreadnaughts who gaurd a shine on one of the shine worlds (Drusus perhaps? I don't recall off hand)
+ Chapters related to the Inquisition could turn up (there's a Deathwatch veteran in the second adventure in "Purge the Unclean") but the don't have a permanent home there
+ Fleet based chapters could always "pass through". Not necessarily "canon" but not beyond the realms of imagination
Lynata
According to the books, the "most elite and dedicated troops in the Calixis Sector" are 50 Adepta Sororitas Sisters of Battle under leadership of Palatine Rhiannon, who are accommodated in a lesser Order Famulous' abbey on Iocanthus. (page 302 of the Core Rulebook)
Nash
If you want you want is simply to have SMs from a chapter who have "a reason" to be in the Calixis Sector, then one of the 4 which participated to the Angevine Crusade would be the best shots (see the Dark Heresy Timeline pdf)... So, Black Templars, Sons of Medusa, Tigers Argent and Charnel Guard are the most likely to have "something to do" in the Calixis Sector
http://www.fantasyflightgames.com/ffgforums/posts/list/6726.page