Definitely go for the partial mash if that's the way you are leaning. I use Deathbrewer's easy stove top partial mash
pictorial. Head down to Home Depot, pick up a $5 paint strainer bag and you're ready to go. Depending on the pot size you've got, you could even mash a little pilsner malt with the munich and wheat. My 3 gal boil pot can hold 5-6lb of grain, and it might help to keep the color down (sometimes lme can be darker than expected, even pilsner).
As for the hopping, I don't see anything wrong with 60, 20, and 5 min. additions if that's what you want to do. Might have a little more flavor than Jamil's version, but I don't know if I've ever brewed a recipe without tweaking it a little. If you do a partial boil and top off with water, it can throw your hops off, depending on how much you are planning to boil. But you can avoid all that hassle (and some of the darkening effects of the lme) by adding some of your extract as a late addition. I generally boil around 2.5gal for a 5gal batch, so I try to add half my extract at the end. Do a quick search for late extract additions and it should help explain it if I haven't done it justice!
Edit: When I say I add half my extract, that would be for an all-extract brew. When I'm partial mashing, I generally try to get half my fermentables from the mash and the other half from extract, so I add all the extract late (half the fermentables).