IMO, if you go all kydex, something like the www.multiholster.com
should work well for appendix carry. Bonus is hes located here in MI. Ive never personally been fond of kydex in a holster... Its to stiff for me.
I am a huge fan of http://www.ubgholsters.com/
. I did recently purchase a "Striker" OWB holster with the 3 slot option of try appendix carry with an XDm, but my XDs rides in a "Canute" when I carry it IWB. The quality of his holsters, for the price, is outstanding.
Also, quality for the money, is http://www.winthropholsters.com/
. Not sure on the appendix options, but I have been pleased with their work and it can be found on Ebay with no "8-44 week" wait time.
I do also have a Remora and I have used it.... But I prefer to have my holsters attached to some article of my clothing. Personal preference.... But the Remora does do what its supposed to and does it well.