ATP is expensive and may not be any quicker.

Find a school that has a full time instructor, (or multiple full time instructors). If you have the money and are ready to go then they should be willing to fly with you every day or multiple times in a day. Ask their opinion for online ground courses and have him fill in the areas needed. Realistically, try to fly at least 3 times a week, more if you can. No reason you can’t be finished with your Private in 2 months. Instrument in another 2 months. Build time over the next couple of months and have the Commercial completed in 4 – 6 months. Get your CFI and teach full time. Full time instructors can average 80 flight hours per month. Within 2 years you can be applying for a Regional Airline job.

Recommendation to save cost in the long run: buy a good used plane. After your training you can probably sell it for the same if not more than what you paid for it.