As for a monitor, it depends what your definition of "reasonable" is. Look around at www.newegg.com or even www.dell.com or something of the like to see what's in your range with good user reviews.
If you go with the LG or something like that however, I'd use DVI as the means of connection rather than VGA. The MDP-->DVI adapter is less issue-prone than the VGA adapter, and will give you better image quality. For some though, 1920x1080 is too high resolution for day-to-day use. If that may be yours as well, Dell has a 1680x1050 20" for $199 as well: http://accessories.us.dell.com/sna/...s&cs=19&sku=320-6523&~lt=popup&~ck=TopSellers
1. the new macs use mini display port (mini-DP) rather than the standard DVI and VGA. It's newer tech, but there aren't really any products out for it yet, so you need a converter cable to go from mini-dp to DVI or VGA.
2. you need a converter cable from mini-dp to dvi or mini-dp to vga depending on the monitor input. DVI is higher quality, so if the monitor supports it (most do), go with that one
3. you plug that converter cable into the computer, and plug the dvi/vga cable from the monitor into the other end of the converter cable
4. the macbook pro can display any resolution available on consumer monitors, so don't worry about if it is supported