If money is no object you can look at CoolShirt systems (stock car & drag racers wear these). I use a Veskimo cooling vest which works on the same recirculating ice water principle as CoolShirt, but Veskimo stopped manufacturing last winter. I do see a couple Veskimo systems still lingering around the internet, but they will set you back about $1000. Other than price, the only other drawback is that you have to set aside some extra real estate on the bike for the cooler.
About 10yrs ago, I was at a track day that was shared with sports cars. One of the female drivers was wearing a close fitting, long sleeved tee that had small gauge tubing sewn to it. She told me that the tubing layout was stolen from an expensive piece of race gear. She did a home-made version for herself. Chilled water from a small cooler was circulated by a 12v windshield washer pump. Quick disconnects allowed her to get in/out of car with near zero hassle. The first one that she made worked too well and had the pattern slightly altered to prevent 'cold spots'. Her cooler holding her ice might have been barely large enough to hold a 6-pac. She said that it was efficient enough that ice would last a whole day of track time. One could make something similar and put a bladder in one's chilled hydration system to cool the shirt's water while still allowing hydration.
This is basically what the Veskimo system was. Worked really well, especially if you could find a block of really cold ice from a bait shop.
I used a surplus RAF shirt which had about 3-4 times as much piping as the Veskimo vest and it worked REALLY well.
The issue was that, ideally, you should use an insulated jacket over the cooling system, which is great right up to the point that the cooling system runs out of ice. Then you're out in crazy hot weather wearing a winter jacket...