Hey man
I have shot a few different thickness shafts on my 145.
To me the sweet spot by far is an 11/32 shaft and I have been shooting it with 4x16mm bands...BUT this weekend I am actually going to reband the gun with 5x14mm bands for a mexico trip the following weekend.
The 4x16 shoots pretty ****in good but I have a feeling the 5x14 will be the better way to go.
I can let you know in 2 weeks which is better haha