This seems like a grreat way to improve on my baking skills by learning from everyone soI'm in! I have Rose Levy Beranbaum's White Velvet Cake in the oven right now (from Roses Heavenly Cakes). Will let you know how it goes shortly!
I just tried a peanut butter cake by a CC member who posts her videos on you tube. She says it's a variation of her scratch yellow cake. I made it this weekend and it's great. Maybe it'll give you an idea of how to change the recipe you're using. This is the link http://www.youtube.com/user/SeriousCakes#p/a/u/0/uQQf3pPMuYUIf the linl doesn't work she goes by SeriousCakes.
If you can get a copy of The Cake Bible by Rose Beranbaum, try the Mousseline Buttercream. It does great in warmer temps. I believe it's an IMBC. It is the lightest shade of yellow and takes color very well. Very tasty and not overly sweet.