FWIW, guys in my club have had good results using light Munich instead of Vienna. Bells also uses Breiss for most of their base malts.
I would agree with this. I brew what I consider to be a dead-on clone and it's just 80% 2-row, 16% Munich I, 4% C20.
+1 I think Munich will get you much closer. That said, I think the key to cloning Two Hearted is harvesting yeast from a bottle. The yeast really lends a lot to the malt profile of this beer. I brewed a clone about a month ago and it's very, very close. Here's the recipe I used:
Bell's Two Hearted Clone
14-B American IPA
Size: 5.15 gal
Efficiency: 80.0%
Attenuation: 83.0%
Calories: 211.02 kcal per 12.0 fl oz
Original Gravity: 1.064 (1.056 - 1.075)
Terminal Gravity: 1.011 (1.010 - 1.018)
Color: 10.92 (6.0 - 15.0)
Alcohol: 6.99% (5.5% - 7.5%)
Bitterness: 60.4 (40.0 - 70.0)
Ingredients:
8 lb 2-Row
3 lb Light Munich
1 lb Caramel Malt 20L
1.35 oz Centennial (9.0%) - added during boil, boiled 60 min
1 oz Centennial (9.0%) - added during boil, boiled 20 min
.50 ea Whirlfloc Tablets (Irish moss) - added during boil, boiled 5 min
.50 oz Centennial (9.0%) - added dry to secondary fermenter
2 L starter of Bell's Ale Yeast
Notes
Single infusion batch sparge
-Add 1/2 tsp CaCO3 and 1/4 tsp gypsum to mash
- 15.6 qts @ 164 ==> Saccharafication @ 151 [60 min]
- 4.66 qts @ 212 ==> Mashout @ 165 [10 min]
- 14 qts Sparge H2O @ 185 ==> Sparge @ 170 [10 min]
Ferment in the mid-60s. Bell's ale yeast takes several weeks to finish fermenting, IME.