Given those specific parameters, I'm not aware of such a comparison. Perhaps, others on this thread can speak to those specifics.
Out of the replacement options listed, I've only had experience with the Audeze pads. What follows is a description of the method I used. This might also work for you.
To attach the Audeze pads, you can either stretch the pads over the stock plastic rings from a pair of HE-6 pads, or as I did in my case, fashion your own rings. To do that, I cut rings out of thick black construction paper (see pic) modeled directly after the size and shape if HE-6 plastic rings. The type of material used for the ring will vary depending on the amount of stiffness you are trying to achieve. Thick construction paper was sufficient for my needs, however a stiffer plastic sheet like that used for binder covers could be used as well. The new rings should provide enough stiffness for pads to hold the proper shape (this was not an issue with Audeze pads as they come with rings), and the rings provide additional support needed for the Velcro dots I used to secure the pads. I inserted the new rings between leather backing and the stock rings of the Audeze pads, then applied four Velcro dots around each ring as a means to temporarily secure the pads. I used 5/8 in. Velcro self-adhesive dots (called Clear coins) purchased from
Michaels. The ones I purchased are very thin, worked well, and were around $3 or $4, if I recall.
I took this approach so I could quickly swap pads for direct comparisons. As I mentioned, there's a chance this method will work for Alpha pads, but I can't say for sure since I've only used this approach with the Audeze pads. It might be worth a try. If you do, post back to let me know if you have any success with this approach. Good luck.
BTW... I appreciate your many contributions to the discussions here on Head-Fi. Several of my headphone purchase decisions have been influenced by opinions that you (and others here) have expressed on Head-Fi. Thanks.