Congrats on coming this far!
I disagree with your coach. You should get a uniform as soon as possible. With the intermediate level, you will be getting into more bouting, and have the opportunity to fence even better fencers. Since you're a sabrist (right?) then you'll know how much it hurts to be whacked real hard. A good uniform just might save you from getting really nasty bruises (instead they'll only be smaller
rolleyes ). I've fenced in sweatpants before, and have had several blades penetrate the fabric and get caught, resulting in broken blades and nice cuts. So you should probably get a uniform ASAP. I suggest that you start out with non-FIE stuff, because it's waaay expensive.
Some good equipment dealers:
http://www.sgfencingonline.com/ - they sell BG equipment for a few bucks cheaper. Blue Gauntlet sells nice beginner equipment for cheap.
http://www.absolutefencinggear.com/ - Absolute is the highest of the low end of equipment. A bit more expensive than BG/SG.
http://www.leonpaul.com/ - possibly the best equipment out there. It's very pricey, but it will last you forever.
http://shop.fencing.net/ - they sell LP and FDN gear for a good price. Their service is excellent; they are a friendly group.
For tips, drills, and tactics, go to
fencing.net. They have a huge forum, and a large training database.