I got my MDR-M1ST from Amazon Japan, paid with Visa Debit (no Credit Card needed) - fast and easy.
Reading impressions here, I also got Yaxi Pads.
1. The Pads. My Yaxi Pads do not look as dramatically thicker as they do look in many pictures online: just 2-3mm thicker than stock Pads. Another thing: stitching on these is a bit wavy and bumpy - overall the quality is not as good as stock Pads, very close, but not the same.
Both Pads were not thick enough for me: tips of my ears would touch inside the cup and hurt. Who "designed" these?! No wonder it hurts: there is nothing over hard, edgy plastic inside the earcup.
Being somewhat a "purist", I wanted to use these "as stock as possible". Yaxi Pads worked, but not good enough. Also did not want to change original sound signature.
I bought 4mm and 6mm Acoustically Transparent Foam for speaker grill covers, which, in theory, should not alter original sound signature at all.
I took original Pads off, traced exact oval shape of inside of the cups and cut out some out of the foam I got. I put my foam between that edgy, hard plastic grill and a Pad: it worked like a dream.
4mm foam insert completely solves the hard internal edges problem (you can sleep with these on now), it raises Pads perfectly enough so tips of my ears no longer touch the grill and I can not hear any changes in sound. If you want to be even more "purist" the design of stock Pads allows for use of a doughnut shaped foam insert (not just oval shaped): that configuration will only thicken stock Pads from the back, which will move grill furter away from your ears and having hole in the middle of a doughnut shaped foam removes any material sitting atop of a driver and make that insert invisible. It's beautiful: foam is not expensive, you can get few different thicknesses to dial the feel in perfect. I would recommend trying 2mm thick foam too: because, for my ears, that would be a better place to start - 4mm is juuust a touch more than I need.
2. The Cable. I have Sony NW-WM1A DAP that I wanted to match these headphones to. It has Pentaconn Jacks in it (Japan made) - so it only makes sense to match it with a Pentaconn Plug.
I also trimmed the cable length from 2.5m to a "classic" 120cm.
I used (in my opinion) the best audio specific solder available: Oyaide SS-47. Japan made. It has 4.7% Silver (yes, you can use some German Solder with 11% Silver, but, because Silver has very high melting temperature it makes it impossible to use without melting plastic on your connectors. "Wetting" of a solder joint becomes harder too). SS-47 Solder also has 4N (99.993%) pure Tin and it's designed to be soldered at a lower temperature, safer for plastic connectors. I used Hozan HS-26 Soldering Iron, with temperature set precisely to 217C Oyaide recommends.
I made cable stress relief to make large opening hole in Plug Shell look good by using tapered round wooden stick and two layers of US made Heat Shrink Tubing. Sanded all over with 1500 grit sandpaper to make it look matte, as close to stock as possible. I also made small black ring to cover shiny gold strip around headphone cup plug, to make it more "stealthy". Later added red strip to Pentaconn shell to match red strip on headphones cups and make it look visually "stock".
Side note: Sony are a-holes for putting glue on stock plug and shell - making it impossible to re-use their shells.
I had a lot of fun making it happen.
though good chance at this point i'll snag an mdr mv1