Sounds like you want a monitor with a high PPI (pixels per inch).
Your original monitor was 17" 4:3 (16" viewable), which at 1440x1050 is 109 ppi. You won't get that in an LCD monitor even if you get something large.
Here are some common LCD monitor sizes (>= 17") that have >= 95 PPI:
17" (5:4) 1280x1024 - 96 ppi
17" widescreen (16:10) 1440x900 - 100 ppi
20" (4:3) 1600x1200 - 100 ppi
21.5" widescreen (16:9) 1920x1080 - 102 ppi
30" widescreen (16:10) 2560x1600 - 101 ppi
So if you want something close in size to your existing monitor, get a 17" widescreen at 1440x900 (e.g. Dell E178WFP).
If you want something with a comparable PPI, and equivalent resolution, get a 21.5" widescreen at 1920x1080 (e.g. Dell S2209W)
If you want something with the same aspect ratio, and a higher resolution, get a 20" at 1600x1200 (e.g. Dell 2007FP).
I would pick the 20". As others have said, you can move it further away from your eyes than a CRT if size is an issue.