Okay. I mainly want to use lightroom so I can just transfer from camera to tablet and the possibly to a hard drive. Can you use hard drives to connect? I'm sorry for all these questions I'm about as tech savy as a rock...
Yes, any Windows 8 tablet based off either an Intel Atom or Core processor is basically an ultrabook without a keyboard, so you can install all the same Windows software and connect to all the same hardware as any other Windows 8 laptop or desktop.
An Atom-based device will generally be thinner, lighter, get longer battery life, and will be less powerful. A Core-based device will be a little heavier, less battery life, but will be more powerful.
So you need to decide what's more important. If weight / battery life is a prime concern, go for an Atom based device (Like Lenovo Tablet 2, Asus VivoTab, Acer Aconia 510, etc). If you want power and battery life isn't as important, go for a Core based device (like Surface Pro).
Some devices, like the Asus VivoTab and Acer Aconia, have keyboard docking stations that have 2nd batteries in them. So you can use them as a tablet while on the go, and then dock them into the keyboard and you've basically got a laptop and they claim around 18 hours of battery life, since you've got 2 batteries.
Also note that some devices, like the Asus and Acer, are so thin that they don't have room for full sized USB ports so they have micro USB ports with a short dongle to convert to USB. Just something to think about since that's something else you need to travel with that could potentially get lost.
Personally I have the Lenovo Thinkpad Tablet 2 and I love it. It's both thinner and lighter than an iPad, yet it's a "real" computer. I get 9-10 hours of battery life, runs all Windows software like Lightroom, etc., has a USB port, has an HDMI port to connect to external monitors and hotel TV's when I travel, has a micro SDHC slot which I have a 64 GB card in, has a digitizer pen, and one of my favorite features, it charges via micro USB so I can charge it with the mobile phone chargers and cables that I already travel with so there's no extra cables to carry. And I can charge it with the phone charger in my car.
The ONLY Windows 8 devices that have software limitations are Windows RT devices. Windows RT devices are based off the ARM architecture, which is basically the same architecture that iPads and Android tablets use. Existing Windows software is not designed to run on ARM, so a Windows RT device will be limited to only using apps delivered via the Windows Store.