Mesquiton,
I won't hide that I like Everett. But in Lilly, you can have your anchor *SP for your Shea team. I strongly believe that, for the same quality, you will have to spend much more in getting non-SP for Shea than in having Lilly 40 starts and buy a cheaper rotation for the rest of the season, and with Buehrle that you recently drafted, and no more *SP of quality for Shea-designed stadiums--or at least none that I can see---We're talking about 80 quality starts.
Clayton won't hurt you in Shea (I had him fourth in my priorities ss-list, after Rollins, Izturis, and Everett), and he's a 600AB+, so you won't have to hire a quality replacement.
So, in my opinion, between these two options:
Lilly + 2 other cheap *SP (1.5M each, on average) + Clayton = 11M, with 5M left to spend on relief\catchers
4 non *SP (2M) + Everett + quality replacement = 11.5M
the first one will give you much more....
Lilly and Clayton for Everett and your next pick, and it's a done deal.