Output from mini displayport to 1600x1200 vga monitor

I recently was given a Gateway VX900 VGA monitor with a max resolution of 1600x1200 that I planned on using as a second monitor to my MacBook Air. I purchased an HDMI to VGA adaptor cable which works well to output from my video game console, but when I use it with my mini DisplayPort to HDMI adapter it has lots of issues such as the top few lines being really spaced out and the fact that it can't display at 1600x1200. Looking on Amazon, all of the mini DisplayPort to VGA adaptors have a max resolution of 1080p or 1600x900 or something of the sort. What can I use to get it to display the full 1600x1200 resolution via my mini display port?