Due to 7d's cropped sensor, you
might want to look at tamron 17-
50. You can probably get it used
for $300. Also, rather than
renting Canon's 24-70 mkII, you
might consider the mkI, Canon ef-
s 17-55 IS, or tamron's 24-70
which also has image
stabilization.. And cost a lot
less to rent. All the mentioned
above are F2.8.