That's some cool stuff! I looked for both of those, but didn't find one before I found the R154 I have. They don't sound like bad choices at all, and if you can buy a QT bell for it, even better.
I wish QT or someone would do up a bell for the R154/AX15/NV3500/AR5/MA5/etc. mounting surface, sure seems like it would have lot's of uses.