Ca articleship

I have been selected for CA Articleship in Sahni natrajan bahl (considered as one of the best firms in internal audit),OP Bagla(one of top 30 firms) and Thakur Vaidyanath Aiyar(One of top 30 firms)...I am confused...In SNB...I am selected in Internal Audit department...I have often heard that Internal Audit hasn't got a good future...in op bagla and thakur vaidyanath..there's no specific departmentalisation...but op bagla and thakur vaidyanath aiyar...have lesser brand value in comparison to SNB...so should I join SNB(Only internal audit with good brand value...actually one of the bests)...or op bagla or thakur vaidyanath aiyar(every tyoe of work with lesser brand value)...Hoping for an early reply