Which type of target archery and which class do you plan on shooting in?
B-Stinger and Shrewd both make very high quality bars.
I shoot freestyle / open class for everything. I can have the longer target bars. I have 30, 33, 34 and a 36 inch front bars. I am using either a 12 or mainly a 15 inch back bar. Indoors the size (diameter) does not matter. For My field target bow, I just bought a small diameter shaft for the purpose of not being pushed around by the wind as much.