Thinking about new cartridge

I am thinking of replaceing old faithful (benz glider) I have a TNT JR/ SME 309/ BAT vkp-5/ ZU xaus phono cable.
I am leaning towards a ruby H .8 output because of only 56db of gain in the vkp-5. I am unsure if .5 output would be enough, if it is it opens up a bunch of contenders, shelter 901/ lyra heikon/ VDH black beauty/ ZYX 100fs-h. I dont want to shell out a bunch of coin and find out later it could have been better.
Also I am concerned which one is a good match to the SME 309 arm. All comments and feedback is greatly appreciated.
Thanks David