I agree with everyone here that recommends the full 5g batch for your first couple brews. It takes the same amount of time as a 1g batch, and I think you will find that you will drink more beer than you think. Just a couple 5 gallon batches will help build up that pipeline (in case you have a bad batch, or can't brew for a while). Then, depending on how fast your first couple batches go, you can move back down to 2-3 gallon batches.
Regarding the Bourbon barrel aged beers, I recommend using bourbon soaked oak chips/cubes. If you want a great first batch to make a bourbon barrel aged beer, I would use Denny's Bourbon Vanilla Imperial Porter, which should be in the recipe wiki. It will give you a great start on your own barrel aged beers.
I think for those who have expensive taste in beer (Barrel-aged, Sours, Brett), Homebrewing gives a great way to make those type of beers a lot more affordable, because you are the one paying the opportunity cost, and that isn't worked into the price of the beer.