Lemon Lime Hefe question

[dreese1986]

I have been interested in brewing SD Slims Lemon Lime Hefe for a while. The extract recipe is set up for 6 gallons. However right now I am only set up for partial boils. Would doing a partial and topping off work okay? Also if brewing a Hefe are there any steeping grains that would benefit this type of brew? Recipe is as follows. Thanks for any help.
All Grain

• 6.25lbs Pale Malt (2 Row)
• 4lbs White Wheat Malt
• 1lb Vienna Malt
• ****Mash 158 for 45 minutes****
• 0.25 Motueka Hops at 60 Minutes
• 0.25 Sorachi Ace 20 minutes
• 0.25 Motueka Hops 20 minutes
• 0.25 Sorachi Ace 7 Minutes
• 0.50 Lime Zest 5 Minutes
• White Labs Hefeweizen IV Ale Yeast
• ****Start Vigorous Fermentation****
• After Vigorous Fermentation subsides, add 1.75L Simply Limeade
• ****Ferment for a minimum of 3 weeks****

Extract

• 7lbs 12.6 Ounces of Wheat Liquid Extract
• 10.7 Ounces of Pale Liquid Extract
• Follow rest of All Grain Recipe