Upgrading from TV to Monitor: IPS or TN?

[KnoVolt]

I currently have this TV
http://www.tesco.com/direct/technika-23-231bl-23-widescreen-hd-ready-1080p-lcd-tv-dvd-combi-with-freeview-blue/208-7205.prd

So I have a pretty bad TV atm. I find there's not too much wrong with the display quality of it. I wish I could measure the input lag or find the response time for it.

So my question is what panel type should I go for when buying a new monitor. I will be gaming on it and watching movies etc. No serious colour work is needed. I'm just worried that since I play some competitive CoD on the Xbox One via the TV, buying an IPS monitor would give me severe input lag.

Is the 'Xms' that is next to the product title on Amazon the measurement of the input lag? And what would you say this TV of mine is at? Will getting a IPS monitor still be better in terms of response time and input lag compared to my cheap TV?

Thanks!

Edit:
This is my list of monitors I am choosing from, probably would lean towards the cheaper of the selected monitors.
http://www.amazon.co.uk/registry/wishlist/T20L08CGFWPR

 

[ONKI]

go for a 120 hz or a 144 hz monitor for gaming if u have the money, it is totally a new level of smoothness.
or u can get an IPS display, LG panels have good color buy 5 ms delay.

 

[KnoVolt]

But does would it have significant input lag? And even then, would it be less than that of my current TV?

 

[ONKI]

which one are you talking about?? LG has 5 ms lag and u wont feel that lag if ur normal gaming.