I have never found a kit that provided what I want, and only what I want. So my recommendation is to build one based on you knowledge and skills. Off the top of my head, companies with interesting option are Chinook Medical, Conterra Inc., SAM Medical, and North American Rescue (NAR).
A basic level of skill should consist of how to do the following with the gear carried: make a proper tourniquet (can be a dedicated tourniquet like the C.A.T. by NAR if you don't mind the weight and single function); how to seal a torso wound (can pack a dedicated chest seal, such as the Hyfin by NAR); wound packing (could carry homeostatic gauze such as Celox); pressure dressings (such as an Israeli bandage); binding a pelvis (could carry the SAM pelvic sling II); and hypothermia prevention (because hypothermia is one leg of the "trauma triad of death").
Notice that this has a heavy focus on trauma. I believe that in the back country, trauma is the most likely preventable cause of death. Also, notice that while I like all the products I listed, none of them make it into my pack. However, with what I listed in an earlier post, I can perform the same functions (and more). I might have to destroy some gear in the process though.
Comfort is more individualized. Ibuprofen and Tylenol taken together make for a very effective pain killer and might make the difference between walking out and being carried out. Basic bandages are both a function of comfort and infection control. Wash a wound well with clean water, then protect it. Things like Tegaderms are great for this as they act like a second skin and move with you. Plus they breath, unlike most bandages.
Antiseptics tend to do more harm than good as they damage your still living tissue. It is better to simply irrigate deep wounds well (think a liter or more of water). Antibiotic ointment is good stuff for shallow wounds, or to coat bandages in to prevent them from sticking to dried blood, I don't normally carry it though. To prevent infection, bandages should be changed at least daily, so I figure if I have a wound bad enough that I need to bandage it, it is time to head for the truck. So, I don't carry gauze either. I can think of what if scenarios where this would bite me, but personally I'm willing to take the risk as it is easy for the what if monkey to add countless pounds to a pack.
I can see Imodium or pepto bismol being nice. Not so much to stay in the field (I think that could turn out very bad), but to help one self extricate. I might consider adding this to what I carry. However, electrolyte tabs and water should be enough to get me back to the truck.
As for something to hold the med kit, I have ditched purpose made bags and pouches for zip-locks.
Personally, I do not carry CPR supplies in the back country. If you want to carry them, Nu Mask is a great option. Near drowning and sever hypothermia are the two situations where I can see myself giving rescue breaths. I'll play my luck if I'm around someone one of those happens to.
Edit: I should have said that I believe trauma is the most likely preventable cause of death after exposure in the backcountry.
Sorry, it just bugged me when I reread my post, and yes that does mean I'm nuts and argue with myself like a padantic mule. End Edit