Updating cab: excellent time for a new monitor?

[Dcpmark]

Currently I've got a Hitachi CM-2112 MU 21" monitor in my 24" cab that I built in the late '90s. Here are the specs:

CRT Trio Pitch: 0.26 mm (Dot)
CRT Size: 21 Inch (20 Inch Viewable), FST
CRT Surface Treatment: Anti-Reflective/Anti-Static coating
Input Signals: Video: analog 0.7 vp-p 75 ohm Sync: H, V separate TTL. H, V composite TTL
Sync on green. Automatic sync mode detection.
Horizontal Sync: 31-107 kHz
Vertical Sync: 50-160 Hz
Video Bandwidth: 220 MHz
Viewable Dimensions: 395mm (Horizontal) x 295mm (Vertical)
Additional Features: Advanced EA-DF electron gun, On-screen display and DDC
Plug and Play support

I am currently running 640 x 480 @ 60hz, although I'm not certain because I think I've seen the monitor display "31/60" and "38/60" at the bottom when the resolution changes from time to time.

I'm fairly happy with this flat screen monitor, but I realized that I could fit a larger CRT without a problem. So, assuming I can fit a 25" monitor in my cab:

1) can I expect much better performance from a different monitor?
2) which monitors do you guys recommend? I've seen these two that are currently available:

http://www.twistedquarter.com/index.php?main_page=product_info&cPath=200_201&products_id=127

http://www.ebay.com/itm/200882116694?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

3) if I upgrade to an arcade monitors from my plug n play monitor, what else will I need to do to make these arcade monitors work in my cab? New video cards, adapters, move to Groovymame or Cabmame, etc?

Thanks in advance!