I think there are a couple of options still on ebay. I found a set about a year ago made by "comet" and sold by "wizbizltd" in the UK I think. I liked them because they used a small linkage on the shifter that kept the main shaft inside the frame like the stock setup. I don't see that these are listed anymore but it might be worth checking with the seller.
Just a note, I do feel a bit more buzz through the pegs compared to the stock rubber cushioned setup. I assume that would be the same for any of the solid mounted aftermarket setups. I'm considering trying to add some rubber washers on the main mounting points to try and reduce that a little.