I would suggest getting trainers made for more "street" applicable scenarios. In other words, 3 to 4 inch blades. Large training knives instill a sense of safety at a distance, which isn't true. Most people don't carry around 12 inch knives either. Spyderco makes a great practice folder, there are other companies that make them but Spyderco seems to be about the standard. I prefer aluminum or other alloys to rubber, but it's a personal choice.
As for training, there are many videos out there and you'd be surprised at what you and a friend can learn from some basic drills and light sparring. Don't limit yourselves to knife on knife, try everything as well as accessing and deploying the blade from your back, stomach, and common holds. Just because what you do may vary from a "professional" doesn't make it bad, there are many styles out there that just aren't suited for reality. Two of these being the videos from Gunsite's Edged Weapons and Kelly McCann's Inside the Crucible.
"Today is victory over yourself of yesterday; tomorrow is your victory over lesser men." - Miyamoto Musashi
[Insert random irrelevant religious quote here]