I suspect Norris is a guy whose price could tumble by tomorrow. Houston has one of the best scouting guys running their shop (Jeff Luhnow, former Cardinals assistant GM) - they are committed to trading anything not nailed down. Look at the Veras move - took an average reliever, gave him a coat of "proven closer" polish and dealt him to Detroit for a couple of prospects with some upside. Norris is not going to be around by the time they are good again, I expect that he could be had for a non-big 4 prospect (Bradley, Cecchini, Owens, Boegarts).
I don't think Boegarts is in Lee talks - Phillies have to know this, and if Boegarts was a deal breaker there would be no rumors. I think any of the other Big 4 prospects and certainly the upper-middle class level guys (Webster, Middlebrooks, Merrero, Britton) are all discussion-worthy. Personally my "prospect order" as far as guys I don't want to deal is: Bradley (some modest major league performance already, hard to find CFs), Cecchini, Owens (always risk with any below AA pitcher that position players don't have) and then everybody else. Also, if I am dealing one of these guys in a package, I'd like Philly to - if they won't pick up salary - at least part with a prospect that the team can dream on (you know, not a Top 100 guy maybe but a guy with something that can project - like Owens basically before the blossomng).