Fred at 4D reamers carries CBI (critereon) and McGowen.
Jimm Briggs carries CBI, McGowen, and Shilen.
Sharp Shooters Supply carries Brux and Douglas.
Sin arms carries Lothar Walter, and I believe McGowen and Bartlien.
I have used CBI, McGowen, Brux, Shilen, Lilja, Benchmark, and Rock Creek. Out of those I found Shilen to be the worst. Jim usually keeps a good selection of CBIs in stock. Fred at 4D has the best reamer selection and will also chamber any barrel make of your choice for a decent price. I recommend staying away from Shilen, Adams and Bennet, Green Mountain, ER Shaw, etc. They are typically hit and miss, every now and then you will get one that's a shooter but usually not the case.