A few tips for buying a reload (and any messenger bag).
1) Ask them to send you the printed catalog thing that shows all the bags. There is a page that shows all the bags on backs next to each other. It really gives you a good idea as to what this thing is going to look like. I believe it also gives you an idea of what the colors look like. Just call either coast and ask for it, I am sure they will know what you are talking about. I got it in the box after I ordered my bag, would have been nice to see it before.
2) Get as many external pockets as you can, I went for the standard custom 2. I have wanted more several times.
3) Use a back pad to prevent weird loads from poking you. I use a rain coat. Double effective.
4) Try to try it on. For me this wasn't an option, so it isn't crucial. But you should ask someone if you could borrow (or trade) their bag for a day. Fill it with some standard load sizes and ride/walk around with it. This should tell you more than just putting it on with their load.