Yeah probably need to focus on 91/135 for now. 135 if you can get it, turbine if you can get it.
Once you develop a track record, some regionals might entertain you. If not the shortage will hit corporate/135 pretty hard very soon, so there will be opportunities there.
Paying for a common RJ type might also get you a foot in the door at a regional but that would be very expensive with no guarantees. But I think somebody would take you since they know you could pass training on that jet.
With all that said... do some careful self-evaluation. It's not uncommon for some pilots, especially older career changers, to have a very shallow climb gradient with turbine skills (I saw that more than a couple times at the regional). If that's your case you'll get there eventually and be a perfectly adequate pilot. But if your fundamental aptitude just can't handle the pace and complexity o advanced airplanes for your own sake, and the pax, you should stick to your comfort zone. You have enough experience at this point to self-assess on that (I'd have to fly with you to even guess).
Also for older folks healthy living in training is a must...
1. Get enough sleep. Like 8 hours.
2. Very minimal booze. One glass might take the edge off at the end of the day. 3-4 will take the edge off of what you learned today.
3. Brain food. 100% not kidding. Plenty of salmon and/or avocados daily. I start on that regimen 2-3 weeks before any training and it makes a noticeable difference, especially for memory.
4. Exercise. Cardio at least five days/week. At a bare minimum hard brisk walks, but try to break a sweat. Reduces stress, improves cognitive function.
5. Stress. Clear your plate obviously. Don't study TOO much, that's counter-productive and your brain will vapor lock. I've literally seen long-time pro pilots who could not recall basic mems and lims because they were cramming so hard.
Do that stuff and your brain will work a lot better. Noticeably better.