Hi dackjemp firstly let me

you to the site hope to see you around

I personaly have never used ultimatesponge.com filters/food, so i cant offer a first hand view, but i have just had a look on their web site, and the fillters look ok to me, regards the food for your discus i would recomend the beef heart flake, for the guppys the tropical flake will do, hope this helps.
Feel free to ask as many other questions as you want, as the hobby has changed a bit since you last kept fish