Soundlab speakers: Castors or Tiptoes?

I recently got an older pair of thoroughly rebuilt A1s in excellent condition and have them set up in the basement. Even though some landscaping work 2 years ago resulted in no more water leakage into the room, I am still a bit uneasy to set the speakers, or anything else for that matter, directly on the floor.

For now, I have the A1s on amp stands with the speakers extending about 4" off the stands on the sides and rear ..... but I know this is not a good idea for a long-term solution. I like the idea of castors, providing they are locking, because of the ease to move them around. But somehow this just seems a less rigid coupling vs cones.

Any ideas or experiences would be greatly appreciated.

I use Walker Valid Points under my A-3s. I got threaded posts for them and then drilled and tapped the wooden bottom and screwed them in. Incredible improvment over the casters. I experimented with the cone locations for several weeks first before actually making them permanent. I can send you the cone placements if you like.
John, the casters offered by Sound Lab are not locking. I suggest the tiptoes. Aluminum is the best for concrete floors.
Thanks guys .... I will get some aluminum tiptoes. And thank you to offer to send the placement with the A3s but I suspect I'll have to go through the same experimentation with the A1s that are a bit bigger.
I agree with Brian - go with the tip-toes (or just about anything else) over the casters. Black Diamond Racing Cones might be an alternative to aluminum tip-toes if you're looking for something more floor-friendly and/or easier to scoot. I think The Cable company sells 'em - get the hard, "fast" ones.