The reaction you had is normal. It will also create kind of a scratchy sensation in the back of your throat if swallowed.
The main issues with the ACV and alcohol related to extraction and preservation. Michael Moore says that ACV is best. An ACV tincture is called and acetum. An acetum typically has a short shelf life. Six months is generally quoted, although I question that. I have Supertonic that is two years old and still good. The alcohol preserves the extract for a longer period of time. I have read that a 50/50 mixture of alcohol and ACV will extract the overall maximum, but I have also read that higher proportions of ACV will do a better job of extracting lobeline, the primary alkaloid being sought from lobelia.
Personally I would suggest the 50/50 split. You get better preservation and my understanding is that you have a slightly better extraction of a full range of medicinal properties. You may get a different answer from different herbalists, but I think the general tendency is towards the mixture. Schulze suggests and uses a mixture, as did Christopher. Since ACV is water based, I would suggest using everclear to bring the alcohol content up close to 50%. Certainly no harm done if you use 100 proof vodka, bringing it to a 25% alcohol content, just my personal bias towards the 50% alcohol content (I've read too many Eclectic Pharmacology books).