I use 3 - Asus VE248H 24" Monitors for Eyefinity @ 6048 x 1080 (5760x1080 w/bezel adjustment). These have a response time of 2ms GTG, Horizontal Refresh Rate of 30 - 83 kHz, Vertical Refresh Rate of 50 - 76 Hz and a Horizontal Refresh Rate of 60Hz @ 1080p which is how they are run. They were on sale for $179 in late 2010 when I bought them but, they are no longer made.
Eyefinity w/3 or more monitors is in my opinion is far more immersive than any single monitor regardless of how high the resolution for that single monitor is and I don't understand why anyone would want to play anything on 2 monitors. For me the logical succession after one monitor is three.
With one monitor directly in front and two more on either side angled slightly towards you it is so immersive that at first you may be in danger of getting motion sickness. It takes some getting used to, It really is that immersive!
You will need an active DisplayPort to DVI adapter for Eyefinity unless your monitors already have a DisplayPort input and for most video cards you also want a DVI input on your monitors.
I like this monitor "
ASUS VG248QE Black 24" 144Hz 1ms (GTG) HDMI Widescreen LED Backlight LCD 3D Monitor Height&pivot adjustable 350 cd/m2 80,000,000:1" @ $269.99 It has it all, Great specs and even 3D and it's within your budget (£200 = $311.60 USD) unless it costs considerably more where you are.
Here are two cheaper choices that have pretty much the same inputs and specs that mine has:
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ASUS VS Series VS247H-P Black 23.6" 2ms LED Backlight Widescreen LCD Monitor 300 cd/m2 50000000:1 (ASCR) $169.99 "
And
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ASUS VS248H-P Black 24" 2ms HDMI LED Backlight Widescreen LCD Monitor 250 cd/m2 ASCR 50,000,000:1 $189.99 "
I hope these are available and within your budget where you live. Good luck!