If you are after a graft on I'd be inclined to see of you could pick up an entire front end - wheel brakes etc and have custom triples made to suit the stock stem.
I agree - it's cheaper and easier to buy all matching parts than it is to mix and match between different models or brands. That way you don't have to modify most of the parts to make everything work together correctly.
The main issue with swapping front ends is not the triple clamps themselves, it's the stem. It's usually either the wrong length or diameter. Even if you have a complete front end with custom stem, you still need to make sure you can mount your headlight, gauges, ignition, handlebars, etc.
I just saw that Style and Performance now sells the triples that I had them make for me a couple years ago. Hornet 900
The product description translates to: Steering Kit for bases to upside-down fork complete with handlebar riser.
They're beautiful triples and everything bolts right on - RC (or Ohlins) forks and wheel, 919 headlight, gauges, ignition, handlebar - but the price has gone WAY up. 540 Euro is currently $776!!
And that doesn't include international shipping and VAT taxes (which can be almost as much as the price of the item!!!).
When I got mine, they weren't offering them for sale on the website - I contacted them and told them what I wanted and asked if they could make it. We went back and forth with numerous e-mails. Eventually I sent them all the measurements of the forks, and asked them to make bar clamps for 1 1/8" MX bars, and anodize everything black. I paid just under $600, VAT and int'l shipping included - it looks like they're at least double that now.
It's sad, because they make the front end swap truly 'plug and play'. A few WT members came over to lend a hand and we had the front end swapped out, and the bike ready to ride in a couple hours.