I don't have any specifics, but I bet you could consult the recipator database for a brown ale recipe. Find one that sounds good, and is attuned to your skill/experience level. Then doctor it. You can use ProMash to get the calcs (the $25 full version is well worth every penny, but you can also use the demo version for calculations, you just can't print anything from it and you can only save recipes 3 times); ProMash will also give you style guidelines for the particular beer style you're looking for. For your edification, I'll post the typical style guidelines for an American Brown Ale below.
As for doctoring, you can simply add some molassas, maple syrup, and/or brown sugar. Also, in my experience, the easiest and most efficient way to increase the body and get a fuller, thicker mouthfeel is to add maltodextrin to the boil. It's a powder that is made from corn, and it consists of complex carbohydrates that cannot be fully fermented. Personally, I like to get mine from www.bulknutrition.com. It's much cheaper as a bodybuilding supplement than it is as a beer adjunct, and it's the very same product.
Anyway, good luck; here are the style guidelines from ProMash for an American Brown:
ProMash BJCP Style Detail
Category: 10 - C
Name: American Ale - American Brown Ale
Style Type: Ale
Color Note: Light to very dark brown. Clear.
Malt Note: Malty, rich. Chocolate, Caramel, Nutty, Toasty.
Hop Note: Hop flavor moderate, medium to high bitterness
Yeast Note: Moderately low to no diacetyl and esters.
Examples: Brooklyn Brown, Bell's Best Brown, North Coast Acme Brown, Lost Coast Downtown Brown
OG (Balling) Min-Max: 1.045 1.060
FG (Balling) Min-Max: 1.010 1.016
% Achohol Min-Max: 4.30 6.20
IBUs Min-Max: 20.00 48.00
Color (SRM) Min-Max: 18.00 35.00