If you haven't done a mash before, I'm not sure this would be the perfect first beer to try one on. You can make good wheat beers with extract: they will taste great, the main problem is they tend to come out too dark, but close your eyes and you won't even notice that :-)
Here's something I knocked up in Beer Smith that would probably get you close as an all extract brew:
- 60 min 2 lb Wheat Dry Extract
- 60 min 2.5 oz Saaz [4.00 % AA] Hops
- 10 min 4 lb Wheat Dry Extract
- 5 min 0.75 oz Coriander Seed (crushed)
- 5 min 1 oz Ginger Root (grated)
- 1 Pkgs California Ale (White Labs #WLP001) Yeast
Assuming a 2.5 gallon boil, this predicts an OG of 12.9 Plato, color of 7 SRM, 32.7 IBU, and 5.29% ABV.
The main thing you won't be able to get close with all extract is the color (note that this is coming in significantly darker than the original). I tried to minimize that by using a late extract addition (note how I put in just 2 lb of extract at the start of the boil, and then the remaining 5 lb with just 10 minutes remaining) which will give you a somewhat lighter end result as it will minimize caramelization of the malt.
You could get even lighter if you are able to do a full 5 gallon boil rather than the 2.5 gallons I used in formulating this, but if you change the boil size, that will also change the IBU. The easiest way to handle that is to enter the recipe in Beer Smith, specify your boil volume, then adjust the amount of hops until you get the IBU you are looking for.
I'm just guessing at the ginger and coriander amounts. 0.75 oz coriander is typical for wit recipes, so probably a good place to start. Get whole coriander seeds (from your homebrew supply store, or any spice market or Indian grocery store) and crush it (so each seed is broken, but it isn't fully ground) in a pestle or using a rolling pin.
For the ginger, buy whole root and grate it (or chop finely) right before you brew. 1 oz should give you a noticeable but not overpowering flavor, but I've heard of people brewing with 2 or even as high as 4 oz, it all depends how dominant you want this flavor to be. You can also get quite different flavors depending on when you add this in the boil: later will be more aromatic, earlier will give you more bitterness and earthy/rooty flavors. I did a ginger brew where I added 1 oz at 20 minutes and a second oz right at flameout, and got a nice balanced complexity from that.
Pacman yeast is sometimes available, but I don't think it is crucial for a beer like this. It's a highly attenuative but otherwise pretty neutral yeast - by all means use it if you can get it, but any neutral American style ale yeast will get you close.