Help with doppelbock

Want to brew my first lager and would like to start with a doppelbock. What do you people think about this:

Malt
59% 11 0 Munich Malt
32% 6 0 German Vienna
3% 0 8 Weyermann Caramunich I
3% 0 8 Weyermann Caramunich II
3% 0 8 Weyermann Caramunich III
1% 0 4 Weyermann Carafa I
Tot. 18 12

Hops
60min 1.5oz 4.5% Hallertau Hersbruck
45min 0.5oz 4.5% Hallertau Hersbruck

Yeast
Wyeast Bavarian Lager (2206)

Original Gravity
1.081

Final Gravity
1.020

Color
21° SRM

Bitterness
22.8 IBU

Alcohol
8.1% A.B.V.

Looks like it should be pretty good to me, but not sure if I should consider more specialty...especially if I do a single infusion mash. I'd like to try a decoction mash, but not sure if it is worth the extra time. I was going to mash at 155 for 60 mins. if I did a single infusion.

Tips? Advice? Criticisms?

I honestly don't think you need all the caramunich. I think the munich & the vienna alone should get you where you wanna go.

I suppose if I went with a decoction mash I may not. I was under the impression that with a single infusion, you needed the crystal to give it color and more complex malt flavors.

I recently did a dopple with:
60% Munich
35% Pilsner
4% Crystal 60L
1% Chocolate

Surprisingly, it turned out to be the maltiest thing i've ever made. The crystal & choc was enough to reach the desired color, while the pils kept it from going overly malty as a 100% Munich (which i've done before & didn't prefer) would be.

Your hop choice seems spot on, as you should be getting around 0.3 BU/SG (around 23 BU in your case).

I don't think you'll need to decoct, given your malt profile & assuming the malt quality is decent. But don't let ME stop you, as there's something to be said for tradition.