I also have ariats and love them. They were a bit narrow for me when I got them (I have wide feet too) but I just put them on, soaked them in hot water for a few minutes, wore them around until they dried, and neetsfoot oiled them and they are really comfy now. I don't think I will get another pair though, too much work to get them comfortable.
I think for wide feet, you need to look at something like the previous posters posted or if (like me) you want something with a thin sole, look into the square toe boots. I don't like to have a big sole on my riding boots so I think my next pair will be a pair kinda like this.
Ariat International - Ariat® Men's Latigo Tall
I think on my next pair, I will probably go with a men's boot. They come in wider sizes. Ariat only makes women's boots in a B (aparently they think all women are supposed to have little dainty thin feet ) and I can get men's boots in my size in a D. Much more comfy.