Hiya. Advice needed please

Hi all.

Picking up a '97 M600 at the end of March (previously owned a CBr6 and Bandit 12, been riding bikes since 1992 on and off) and I am asking advice on fitting a tacho.

While a tacho is not essential, it would help as I am deaf and a v-twin vibes more than a straight four

Have been doing some research into this and Datatool do a Rev Light? Does anyone know if this is any good and how easy it is to install. Alternatively, what about fitting a combined speedo and tacho unit - I have seen a few on eBay.

Any advice would be much appreciated.

Cheers.