YinHoNg - I agree with those 2 options. I bought a Bulldog desk from Staples a couple of years ago. It has a substantial steel frame and seems ok with lots of weight, (you have quite a heavy monitor there). Also the slide-out keyboard tray seems very solid - that is often a design weakness with that type of desk. However with your budget you will have no problems.
I recently looked at desks with a glass top, the monitor being mounted on rails underneath the work surface. They seemed to give a good working space, and the rails would have fitted my 19" CRT - I measured it! My monitor is a LG Flatron 915FT, by the way.
I don't know the maker(s). The desks were on sale at PC Parts, Stockport.
Well the layout is your personal choice but your desk really needs to be solid if you are putting a 19" CRT on it, so you need to see it "built" - a picture is not enough! Not sure that Argos would have a range of desks out on display would they?