This is where I have been looking actually. Have you had good experiences with them? Any recommendations on which gold or silver bars to purchase from them? There are so many different choices...
I have ordered from them. I paid with a check (takes about 3 weeks to get your order) but you get a better price than when you use a card.
I would say look at buying American Gold/Silver Eagles or Canadian Gold/Silver Maple Leafs in whatever size you want. They are the easiest to move, and are always going to stay at a higher premium over spot than generic rounds.
If you want others (bars, generic rounds) you can get them a little closer to spot, but I would recommend keeping your collection to 50% or more of US/Canadian minted gold/silver.