All the ones I have personal experience with have long since been discontinued. I have a suggestion on how to greatly improve your performance from a standard soft pad. You can read about it here:
http://www.pnwbemani.net/bemani-discussion/home-built-pads/msg29748/#msg29748

However, as far as buying a pre-made soft pad that will let you do 10's well...that might be tough. Even the Ignition pads back in '04 (my personal favorite "soft pad" with foam insert) wouldn't be the best for trying to score attack a 10. I think my suggestion in the post I linked to might be your best bet at something light weight, but stable enough to do that with. You will wear the pads out quickly doing 10s on it, but the good thing is that soft pads are cheap, so you (in theory) could just replace them as needed to keep it running at peak ability.

I suppose I don't need to practice FAs on these things. It's impossible for me anyway, but I am searching for a pad that's decent for kids who have no idea what they're doing playing DDR to use. I'll occasionally use it with them to show them the harder songs.

i still use a gamestop soft pad, i passed everything on itg 1 home and i aaa'd pretty much all of 5th mix home except radical faith on that but i had to tape it down onto this wood board so it wouldn't move around too much. depending on how you step the pad can last years: mine has lasted about a decade and i haven't needed a new soft pad. if you can find a soft pad like this i'd recommend buying it, but i think the one they made after it (the gamestop light blue model) is the common one. given where you are at in dance games it's a matter of stepping correctly on a soft pad... but that isn't really necessarily how you want to step at the arcade. you have to weigh practicing at home but not having how you step carry over to the arcade. since you seem to be progression oriented i'd say build a metal pad or mod one so you can play as you do at the arcade at home.