First of all, you have a gold mine of a team for a 15 person league.
You can only keep 7 players, so you have an interesting situation, you can have trade now that you necessarily wouldn't accept in the regular season. You really don't have any interest in keeping your #8, 9 and 10 around, unless you know something about your chances of drafting them (a simple i.e., you have first pick in the draft and you can pick Nevin, but if you trade him to Jimmy, you obviously can't pick him).
Without trades I probably would keep Nomar, Ordonez, Abreu, Gonzo, Morris, Oswalt and Vasquez. But if you don't accept either of the trades, you are wasting 3 quality players, that do doubt are in the top 105 players (15 teams X 7 keepers). So, you have to go with a trade or two.
If you took only the Arod trade, you have Arod, Nevin, Ordonez, Gonzo, Morris, Oswalt, Buehrle, Vasquez and Wolf to choose from. I probably wouldn't keep Nevin and Wolf from that bunch.
If you took only the Helton trade, you have Helton, Nomar, Nevin, Ordonez, Abreu, Morris, Oswalt and Wolf. I would probably leave off Wolf.
So, here are your options (feel free to substitute for my keeper choices...
Nomar, Ordonez, Abreu, Gonzo, Morris, Oswalt, Vasquez (Nevin, Buehrle, Wolf not kept)
A Rod, Ordonez, Gonzo, Morris, Oswalt, Buehrle, Vasquez (Nevin, Wolf not kept)
Helton, Nomar, Nevin, Ordonez, Abreu, Morris, Oswalt (Wolf not kept)
A Rod, Helton, Ordonez, Nevin, Morris, Oswalt, Wolf
I would go with both trades, giving you the best SS, the best 1B, a top 5 OFer, 2 top 10 pitchers, and 2 other solid players... Just my opinion.