OK. Few points.
*To say that business models are behind on spec is somewhat wrong. It IS hard to gauge because business lines don't have the same wide distribution channels as consumer level gear, so business models that are listed on sale retail tend to be older stock. Sound cards are a pretty standard thing now across all machines I see. There is about 3 common chipsets, and everyone uses the same ones. Basically, not a concern.
*Even if they are slightly behind on spec with something like a video card - it doesn't really matter, because they are still going to have more than enough grunt for the sort of work you're talking about.
*The best way to access a full range of business models is to go direct to corporate reps. I can tell you that with Dell, talking to a rep usually gets you a better price than the website too.
*As noted, consumer models miss out on stuff like docking ports. While it IS easy enough to plug in an external monitor and usb mouse/kb (Use bluetooth mouse in reality), I have not regretted moving to a proper docking station one little bit. It's SOOOOOO much better. Don't even have to put the machine to sleep, just slap it down and automatically my external LCD, speakers, gigabit network, keyboard, iPod dock are all connected in seconds. It's SO worth it if you're doing it every day. If not....well it's a toss up.
*Design - yes consumer models are prettier. What are you, a fuckin girl? If you want a pretty laptop, just get a fucking Macbook Pro

Business models are more conservative design because the models stay around longer and you end up with parts commonality across the range. In my experience, business models are more rugged and more solidly built and last longer.
*Warranty - this is the #1 best part about business models. Sure, default is usually 1 year return to base like consumer models, BUT business lines give you the chance to upgrade to way better offerings. You can upgrade to 3 years, or do what smart people do, and upgrade to 3 year onsite support. It breaks, you call, motherfucker turns up at your office and fixes it for you then and there. Pay enough, you can have them there in 4 business hours, 24/7. Next business day is most common option. Yes, you pay for this privilege, but if you rely on your machine enough, it would probably pay for itself even if you only used it once over the life of the machine.
*Leasing: This won't really make that much sense in a situation where you're only talking a half handful of machines, but it may be worth looking into. It moves the cost of the machines from capital to cashflow, and structured right, the insurance burden is placed on the lease company not yours. Doesn't sound like a big deal, but in our case, it means a stolen laptop costs us $100 excess, not the $1000 it would claiming it on our own insurance. After 3 years you roll over the lease and get a brand new machine.
*Brands: HP and Dell would be the only two I consider in this market. Toshiba would be 3rd, but lately their service hasn't been as good as the other two. (I've dealt with all 3 a lot over the last few years.)
As for me, I have a slightly older HP EliteBook 8530p.

Core 2 Duo 2.53, 4gb ram, ATI Radeon HD3650 w/ 1680x1050 15.4", 320gb 7200rpm, E-SATA, HDMI, fingerprint, touchpad and trackpoint stick, webcam, BT, blah blah all the standard stuff. It's awesome and still performs really well even with what is essentially 2 year old spec. And I still get pretty sweet battery life out of it, 3.5hours+ with no performance degradation because of overly aggressive power management, which I consider good. Runs cool and quiet too, fans barely ever come on.