Recommend me a montior for my early 2013 15′ Macbook Pro Retina

Hello I have an early 2013 15″ Macbook Pro Retina and want to buy an external monitor 24″ to 27″ I think. My knowledge of Thunderbolt is VERY flakey though and so I don’t know where to start: 2. Note according to this I have Thunderbolt 1 which I think limits me somewhat I don’t know how? I read something about 10GBPS or 30mhz? 3. I run my 15″ Macbook screen at it’s native resolution of 2880×1800 and like that.