a nice new cobalt bit will drill that just fine. Just my opinion but I would either have a fab shop weld up an elbow or order one the right degree. I know when you get this close you want to get it done but it's not that cold out, take a breath and do it right.
It doesn't have to be stainless, mine is made from 3/16 steel. I have a church friend that has a fab shop.
Dont know what to do. Cant get it to sit flush the clearance to install is crap and im starting to get frustrated...
Also, found these in 15 and 30* Elbow - 30 Degree | WoodlandDirect.com: Chimney Liners heres the one on fleabay (hope this link is ok here, if not mods delete it please) Heat-Fab 4609SS Stainless Steel 304 6" 15 Degree Crimped Elbow and Heat-Fab 4610SS Stainless Steel 304 6" 30 Degree Crimped Elbow
FWIW, in my install (same stove), self tapping screws and a cordless screwgun were all that was needed to get things fastened.
If I were you, I would think about making a convection deck to get the most heat out of the fireplace. The blower does a very crappy job blowing air across the stove top. It blows more air up, than out. Some plate/flat steel and a piece of 4" rigid dryer vent (cut it in half and use for the sides) makes almost all the air come across the stove top and will get it out into your room. I did it for the added heat. It would be a must for me if it was in a fireplace.
Well the 15 degree elbow arrived and worked like a charm! Got it all seated and installed. 59 in the house do FINALLY started the first fire! I cannot thank everyone enough. You all have helped me so much and it truly is appreciated. Im sure i will have many more questions down the road and know I can get them answered here!