My N8 (Nate squared at
http://n82tactical.com/) is a little bulky but "ok" for appendix carry (shown here w/SR40c)... A sturdy belt is important:
In cooler weather, my inexpensive Blackhawk Size 1 works good for shoulder carry with a light jacket, and for all-day is preferable to appendix carry comfort-wise... (To me, double-stacks are a bit much for appendix carry so I don't do it for long periods.):