Okay, quick primer on tripod and heads.
Couldn't find specs on that combo via the BB website, but here's the same combo with some specs that we can discuss:
http://tinyurl.com/ybfdxvw
First off, let's take a look at heights:
closed length: 20.00 in
maximum height: 56.22 in
maximum height (with center column down): 48.74 in
minimum height: 14.49 in
It basically collapses down to 20", which you can pretty easily fit into a standard size carry-on suitcase. If you're going w/a 18", then place it on the diagonal.
14.49" is the minimum it can get down to, so if you're shooting something that low (macros), then that's out of the question. Lastly, max height and max height with center column down. I usually use the figure closer to the tripod (with center column down) since you will get more stability vs. when the center column is all the way up. Also importantly, not sure how tall you are, but at 48" it's not very tall and you will most likely need to stoop down to use it. Once or twice, not a big thing, but if you have to do it continuously, then that can be an issue. I prefer the height (use a figure in between the two; in this case, about 52", or 4'4") to be as close to eye level as much as possible.
Center column: Mainly used to adjust the height of where the head (ballhead, pano-base, etc.) sits on the tripod. A good option to have is a center column which has a hook on it. Why would you want a hook? It's good for a couple of reasons: 1) use it to hang your camera bag (get the weight off your back, get your camera bag off the mud, water, or whatever your tripod is currently standing over, easier to rummage through your bag), and 2) the additional weight of whatever is hanging on there stabilizes the tripod.
Lastly, let's take a look at weight bearing.
load capacity: 7.72 lbs
7.72 lbs. I prefer to go with a value that's usually 2x the weight of whatever I want to put on there, just for safe measures. Not sure what you shoot with, but let's take a look at possible setups - Canon/Nikon (C/N) C 50D/N D300 with N/C 18-55mm lens, C 17-44 mm EFS, N 17-55mm AFS, and the ever popular 70-200mm f/2.8 AFS/L. Camera weight used in both cases are
without accessories (no batteries, flash, etc.).
C: 50D + 18-55mm: 25.7 oz. + 7.1 oz = 32.8 oz or ~ 2 lbs.
N: D300 + 18-55mm: 29.1 oz + 9.3 oz = 38.4 oz or ~ 2 lbs.
C: 50D + 17-55mm: 48.5 oz or ~ 4 lbs.
N: D300 + 17-55mm: 55.7 oz or ~ 4.5 lbs.
C: 50D + 70-200mm: 78.3 oz or ~ 6.5 lbs.
N: D300 + 70-200mm: 83.4 oz or ~ 7 lbs.
Looking at those numbers, if that's all you can fit in your budget, and if you don't have any lens larger than the consumer zooms, you should be okay. Those weights are for bodies only and without accessories. You stick a battery in the cameras (or body grip) and/or a flash on there and you can up the weight a bit more (~ 1 lb. for flash alone).
If you plan on sticking a pro lens on there like the f/2.8 zooms of any sort, I would take a look at a different legs/ballhead combo. Speaking of ballhead, the small ballhead on that combo leaves a lot to be desired.
Do it right the first time. Spend the money for the tripod legs and ballhead once and they will last you a long time (you buy certain lenses a few times just to figure out shooting styles and so on, but a support system lasts pretty much a lifetime).
Looking up the tripod on Manfrottos' site, the legs on that combo you're looking at come in at ~200 by itself. For around the same price, I would take a look at one of these:
http://tinyurl.com/ydbkeko
I've owned the 3401 for a number of years now and would buy another in a heartbeat if something was to happen to mine (I'd look at the 3402 if you're looking at the ~$200 range). The ballhead on the other hand, I prefer arca swiss clamps vs. the manfrotto/bogen system (dovetails vs. square plates). For the price you're looking at, I would stick with the manfrotto/bogen system and just about any of their $50 or so ballheads would work (again, take a look at weight bearing on the head).
Lots to digest above, but hopefully it's useful.
