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.
+1 on the criterion, I have one on a 116 in 300 win mag and it shoots lights out, also have another one on order from criterion that is gonna be a 6.5WSM it should be here in the next few weeks and I can't wait. They are a GREAT barrel for the money.