Can you recommend a good but inexpensive external 24" monitor or similar to hook up to my 2015 i7 3.1Ghz MacBook Pro 13"? HDMI or Thunderbolt Port and how?

I have a 2015 13" i7 Processor Macbook Pro 3.1ghz with 2 Thunderbolt2 Ports and 1 HDMI Port along with 2 USB3.0. Im looking to hook up an external monitor, approximately 22-26" to this MBPro and was wondering if hooking up thru the Thunderbolt2 will give me a higher resolution and refresh then the HDMI port? I do photography editing but on a limited budget so I need to get a good quality monitor but can't afford the Apple external. Can you recommend one and directions on how to hook it up? I am running the very most current OS X Yosemite Build. My internal display card is the Intel Iris 6100 Graphics Card with 1500gb of onboard memory. I have 16Gb of DDR3 on board and the 500SSD.

People tell me NEC, Dell and LG monitors are good but not any model info and I see that under Thunderbolt 2 I can get a high resolution at a 60 or 30hz refresh rate?? Which is better refresh and should I go with a higher resolution with slower refresh or visa-versa but still looking to stay under $500.00 USD I hope???

Thanks my fellow Mac Community!!!!!