Hefes are usually brewed with one of the German "noble" hop varieties, most often Hellertau/Hersbrucker and/or Tettnang. Because they're only used for bittering and not as flavor hops, the most important thing is that they're all low alpha (3-5.5%), while you're Sterling is high alpha (6-9%), so it has a lot more bittering power.
Since you want to work with ingredients you have on hand, you can probably brew a to-style Hefe with Sterling, but you'll have to cut the amount. If you don' care if it's to style, you can do whatever you want (of course).
Hop schedule is going to depend on how you brew (full/partial boil, early/late extract addition, etc), if you want to get an idea of what you'll get out you can go enter your conditions in the beer recipator:
http://hbd.org/cgi-bin/recipator/recipator
Putting your recipe in as an extract-only, w/full 2.5 gal boil and assuming avg attenuation (FG = 1.012) gives me:
OG: 1.052 (5.1% ABV)
SRM: 2
IBU: 35
That's going to give you a light, bitter, wheat. If you want something closer to style, cut the sterling hops to a single addition: 0.25 oz for 60 min. If you're not doing a full boil, you'll have to adjust things a bit to figure it out, but you want 10-15 IBU, not 30+.