Ten feet wide? My god man, you probably need egg!
Kidding aside, are you burning pea now? If so it sounds like its working. The nut may be a better choice, I'm not sure why you want to stick with pea. Anyway, mixing it won't be a big deal. Try it 4 parts pea to one part nut if you want. The nut is bigger and will leave bigger gaps allowing more air to get through. If it burns fine with pea, just fill it up and enjoy it. Without any refractory, be cautious of overheating it though. If the stove starts to glow, usually at the base, you will need to be careful. Nut will probably burn hotter than pea, so I would think that if your going good now, your probably all set.
I don't think you will get clinkers from smothering it anyway, those stove seem to burn very well and leave a fine ash. I would not expect many clinkers with decent coal.