Banana Bread Help

So, I used to make a damn good banana bread. Unfortunately I have misplaced the recipe and have been on a mission, for about a year now, to find something comparable. My dear friend the Beav (Kate) makes the best banana bread my HUSBAND has ever tasted (OK me too!). Beav brought over her tasty loaf (of bread) and as he dove into it says "oh honey, you have to get this recipe!"

All right, I know where she got the recipe, so I thought I would give it a whirl. This recipe is from Lance Armstrongs mom. Beav read the book and got it there, I got mine from the Internet doing a Google search on "banana bread Armstrong". Hopefully it was the same one.

So I have all the ingredients for this except buttermilk. I hate it when a recipe calls for something that I don't normally have in the house. Who has buttermilk in their house on a regular basis?? Anyway, I figured there must be a way to find a substitute for buttermilk. So on Cooking Light 101 they say you can use 1 tablespoon vinegar and then whatever milk you have to create 1 cup. I was a little worried when the batter seemed to be separating a little, kind of like oil and water together. All in all it turned out OK, not the best, definitely didn't taste like the Beav's. Next time I will make the trip to the grocery store. But here are my other problems that I have been having. It may be due to a crappy old oven that doesn't cook evenly but maybe someone has the answers for me.

1. The bottom half of the bread is always darker than the top half. Is my oven rack too low? Too high??

2. The top browns much too quickly? Can this be solved by tin foil?? Lower temp, longer cook time?? Oven rack too high?

Maybe I just need a new oven!