Nice specs!
The only thing to take into consideration is cooling. Two hard drives will add to the internal temperature, especially if they're crammed in next to each other. You choice of graphics card will be crucial too. You don't want something too excessive in there because it will get very hot. I'm guessing you're dealing with low-profile cards, which means you should find a nice compromise as excessive power doesn't really go hand-in-hand with smaller cards.
One more note: any large PCI cards may obstruct the GPU cooler, which is not desirable if it can be avoided; I've seen a GPU cooling fan melted off its bearing due to this, it was dangling onto the sound card that had been put directly underneath it!
RAM with a discreet heat spreader would also be a good choice.
The ESI Juli@ is an interesting card! Its nice that you can swap between balanced and unbalanced I/O by physically rotating half of the card, and the DirectWire feature is incredibly useful. It seems a solid choice for analogue capture.