Ok so this is now done, it didn't turn out quite as I had hoped but its pretty cool
I used an SRAM X9 gripshift fitted upside down so to speak on the left bar side and a Suntour (urgh) trigger shifter next to it for the front three. The Suntour was the only one I could find that had both trigger levers in a 'push' configuration from the front; no need to pull the rear lever. This meant it would fit and work alongside the bulbous nature of the gripshift.
I made it harder by using a Hope brake lever which took up a lot of room. I had to grind/slim the cable adjuster on the Gripshift and take a little off the 'paddle' on the Suntour shifter so it would pass under the gripshift.
I used an SRAM X9 gripshift fitted upside down so to speak on the left bar side and a Suntour (urgh) trigger shifter next to it for the front three. The Suntour was the only one I could find that had both trigger levers in a 'push' configuration from the front; no need to pull the rear lever. This meant it would fit and work alongside the bulbous nature of the gripshift.
I made it harder by using a Hope brake lever which took up a lot of room. I had to grind/slim the cable adjuster on the Gripshift and take a little off the 'paddle' on the Suntour shifter so it would pass under the gripshift.