I'm very happy with my Old Faithful IWB for my Nano. I used it the past 2 weeks every day, and it was quite comfortable. I didn't think the Nano needed to spread the weight across 2 belt clips but it made it very secure and comfortable. Plus it's tuckable so I was able to wear it in the office without any notice.
The quick assembly kit cost me a but less than $50 delivered. I recommend them to anyone looking for a hybrid IWB holster.
SIG 1911 .45 ACP
SIG P229R 9mm
Beretta BU9 Nano 9mm
Beretta 84FS .380 ACP
Ruger MKIII 22/45 Target .22LR
PWS (Primary Weapons Systems) MK114 5.56