Thunderbolt 2 / Minidisplayport Cables??

Hi, I am hoping someone can help me please.

I have a 2015 MBA which has one Thunderbolt 2 port. I currently run it with a Dell 27 inch monitor via a genuine Apple Thunderbolt to VGA converter, then a VGA cable into the monitor.

I hate the conversion piece, I am obsessive with the looks of my desk. Recently I purchased a Startech MiniDP to VGA cable, the image is terrible / stretched and unreadable. I went through all of the settings and changed resolutions but it did not work. Despite their website saying it does, it also says it covers up to my monitor's resolution.

I've read online that of course there is a difference between MiniDP & Thunderbolt 2 and certain items can not work dependent on which connection you have.

My monitor has a VGA / DVI / Displayport connection. What I am looking to do is have one cable coming from my Mac without a conversion piece on display. I've been onto Amazon for a Thunderbolt to displayport and all of the cables showing are MiniDP (which say they work with Mac) but not saying Thunderbolt. I've also looked at a Belkin MiniDP (again MiniDP not thunderbolt) to HDMI and then a HDMI conversion to displayport hidden behind the monitor.

Does anyone have any recommendations please?