If I were in your shoes, I'd give the
Kimber Pepperblaster some consideration. If not interested in that, just ensure that the OC you do carry fires in a direct bead, rather than a spray cone. That will give you much better range and will significantly reduce (though not eliminate) your own suffering when you fire it. Therein lies the problem with OC spray, IMO at least: Both the target
and the user will feel some of the effects.
If you've ever been sprayed with OC, or used it on someone else, you know what I'm talking about. If you haven't been sprayed, and you plan to continue carrying it, you should seriously consider convincing a close friend or family member to spray you in the safety of your backyard. That experience isn't going to reduce the effects of it in the future, but it will give you the advantage of knowing how you react to it, which will reduce or eliminate panic if you end up using (and therefore feeling) it in the future.
If you decide to do this, the setup is simple. You'll want a hose turned on and laying in the grass close (10ft or so) to where you get sprayed. Follow the instructions on the canister regarding use (distance, method, length of burst) when you're sprayed. After you're sprayed, you'll want to rinse your face and eyes thoroughly in the hose. Stay outside until you can keep your eyes open to see well enough to function on your own. This time varies from 10-35 minutes or so, depending on the person. Have the friend or family member who sprayed you stay with you during that time, possibly fan you with a small towel. After that's done, go inside and take as cold a shower as possible. Note that water does activate the spray, and will reactivate it in the shower (it will have dried during the 15-35 mins outside). Wash thoroughly with Johnson's tear-free baby shampoo. Rub the soap into your open eyes, and flush thoroughly. After the shower, just lie down under a ceiling fan for an hour or two. The burning should be completely gone by the time you wake up next day.
Obviously that doesn't sound like much fun, and in my experience, it's downright awful. It's also totally beneficial to any user, which is why all LE who carry it are forced to go through this process.
Short of all that, carry a collapsible baton and a knife. A fixed blade is a good idea. This
Ka-Bar TDI weighs just a few ounces, is built very well, and is designed for self-defense.