Originally Posted by Lcasanova
So then the 1st experiment should be 100% BRS...what style shall it be?
If these experiments are to be useful they need to all be the exact same style, hops schedule, and yeast.
The only way you can tell what is the difference the grain makes and what are the style differences is to keep that consistent amongst all the different varieties. While it might not be always the most interesting beer possible, in this case the fewer variables the better.
Malt: Focus on light-malts so that some accidental over-toasting doesn't throw off the flavors between batches.
Hops: Keep it a fairly mild variety and don't let the hops be dominant, but still good enough that you'll enjoy the final product.
Yeast: Safale US-05 or S-04