Try the g502, they have the exact same sensor and are pretty much the same size. However, there is no doubt that the g900 is far superior if you are an FPS esports gamer.
Why are you trying to get your rx 480 to throttle? I'm not sure if not throttling is a bad thing, but if anything it should be a good sign about your thermals and cooling.
If you have a dual bios card and you don't mind flashing, try flashing your card with an rx 580 bios. You could get some decent performance boost because i'm pretty sure the red devil card is a higher binned card.
Do you have a costco membership or know someone that does?
https://www.costco.com/Dell-SE2717HR-27"-Full-HD-Monitor.product.100337050.html . I'm pretty sure this is the exact same as the one i have (se2717h/hx), i'm not sure why it's called HR. AFAIK h vs hx is just VGA vs HDMI wire included in the box.
If it is the same one, it's a great deal because its an IPS 27" 75hz 1080p with freesync from 48-75hz for 150$ (I've heard this can be downclocked to 30-60hz but haven't done it myself). I got it myself for 120$ about 2 months ago but that sold out really fast from staples. I sit about 2 feet from my monitor and the 1080p at 27" doesn't bother me at all, but some people swear at 27" you need to have 1440p. The only downside to this monitor is that it has only one HDMI and one VGA.
EDIT:
Also Dell's dead pixel policy is really stupid, they won't exchange it if it's <5 dead pixels. So make sure you check your monitor and get it exchanged at costco before your return/exchange period is over if you have any issues with dead pixels. Apparently most monitor companies have this <5 dead pixel policy, nevertheless if you have them make sure to get it exchanged from the retailer.