Forgive me if this sounds harsh, but have you done any research? You say
"Basically, I was convinced that I should get a 19" lcd (I'm either considering the ibm monitor for $550 or some offbrand costco model for $500)"
but that tells us nothing. A $500 monitor could be worth $600 or $200. At the very minimum, we would need to know brand, resolution, and response time on the monitor. For $500 at Costco, I'm expecting something along the lines of an NEC, 1280x1024 resolution, and a 25ms response time. Am I right?
As to your widescreen question, it's really a matter of preference. Sure it may be a little nicer in movies, but you really shouldn't be putting down much extra for it. Again, what percent of time do you spend on gaming, working (let's say working is text editors), surfing, photoshopping, watching movies, and other? I'm personally a fan of "widescreen". My current resolution is 2560x1024, courtesy of two 18" Dells (I believe they're rebadged Samsungs). Even then, when I use my laptop at home, I don't bother hooking it up to a monitor. Maybe I'm just weird

What kind of resolution are you after? If you don't know what resolution is, don't bother answering: it won't be important.
As per widescreen LCDs having TV tuners, those are LCD TVs, not LCD monitors. I would highly suggest against getting an LCD TV, unless you/your parents are
loaded, as a decent one is too expensive for most college students. Were I inyour situation, I would either get a nice 19: CRT (if you have room) and save some money, or if you're not paying for it/need more space and are a hardcore gamer/movie fan, a nice Samsung:
http://www.samsung.com/Products/Monitor ... 72X_sp.htm
The 171 has a 16ms response time if you don't want to spend all that money on the 12ms time

Or if you just want a solid performer for everything, my 1800FPs from Dell are very nice.