I guess your best bet (that I know of) for a realistic costume would be either Clockwork creature or Beastcub. There isn't really too much info available so I can't really tell if you're after a quadsuit (4-legged) or a normal 2-leg suit.
Clockwork currently only makes 2-leg costumes, but when it comes to realism they're second to none, and they've had their costumes featured in a film before.
Beastcub makes some of the best 4-legged costumes in the fandom, and they're quite realistic too.
http://www.clockworkcreature.com/http://www.beastcub.com/Sadly both of them appear to not take new orders at the moment, but CC is open for quotes and BC opens in October.
When you say "very soon" it kinda sounds like it'd be hard or even impossible to get ahold of a good well-made custom suit tho. Most makers usually need about month or two minimum to make a suit from scratch...