Lost_luggage34,
A 17" TFT with Onboard Video will still look great. Even when you pump TV though the PCI Card to the TFT, you will not have any problems viewing it.
As a rule, a 17" TFT lets you see the full 17" Diagonal, while a 19" CRT will only let you see just short of 18" Diagonal. So a 17" TFT is very close to a 19" CRT. The 19" CRT is cheaper than the 17" TFT but will take up a lot more room on your desk.
Either option comes with trade offs, you just have to figure which trade offs work best for you.
Take Care,
Richard