Trawler Fest is a really good place to start. For about 3 years in the early days of TF, I was one of their core presenters and did Boat Buying 101. Some observations from the little I've heard
1. Budget. You're looking at under $100k, at least right now. No problem, there are some nice boats out there in this budget.
2. Large dog. This rules out boats like aft cabin or motor yacht styles unless they have a cockpit extension.
3. Loop. I've never done it, but I understand you need range of around 400nms and your air draft is limited. I forget exact number, but in the 19 foot range (check to be sure). This rules out most boats with a hard top or mast. As a sidebar, it's not too difficult to temporarily reduce air draft by hinging down an arch as long as it was part of the original design.
4. Recovering sailor. Couple of generalities. In my experience, Sailors want the redundancy of twins. I think it's because many sailboats have under-engineered power trains, many sailboats have lousy engine access that discourages maintenance, and the usage cycle in sailboats is poor. In short, if I took care of my single engine diesel the way Sailors do, I'd want redundancy too. I'm not here to kick off a long debate of single vs twin, just to recognize that you do have to make a decision what is acceptable to you.
The second part of being a recovering sailor is speed. On the good side, most Sailors consider consistent 7 kts acceptable. But not all.
Finally, you probably already have an idea of how you will use outdoor space. Covered sailboat cockpits are pretty inviting spaces.
5. Outdoor space and how you'll use the boat. I like a flybridge for navigating in good weather. But I don't find it good space for hanging out at anchor. Personal preference. I live in Florida and believe nice covered outdoor space is important which is why I like a sedan. Pilothouse layouts have a nice covered aft deck too. Trunk cabin trawlers like the CHB 34 have side decks and a flybridge. You need to decide if that's acceptable for your destinations. I personally like a lot of shade. Trunk cabin trawlers don't do it for me. If that's what I had, I wouldn't swap out. But it wouldn't be my first choice. But that's really personal that is different for everyone. Folks on lists like these will forcefully tell you why their decision is good. All I can say is why we made the decisions we made.
6. Speed. So I said above that Sailors are okay with trawler speeds. But it sounds like you're not retired yet. Time may be a precious resource for you. If you're doing trips of 3-7 day vacation trips, well, 15 kts nearly quadruples a the area you can explore if your time is limited. Yes, it's more expensive from fuel burn and it means twins, but if time is contained, might be a good value overall.
7. Budget. There was recently a Defever 40 listed on CruisersForum (sister site to this, though more sail oriented). Owners had just completed a 2 year cruise from San Diego to Miami. $50k. Good deal and likely on good shape. Goes up from there
So that's my best thinking. Figure out your constraints like the dog (getting on /off via dinghy). Go to a trawler fest and attend their seminars. They appear to be a bit sales oriented compared to the old days, but likely valuable.
Finally, this forum is a great resource. Once you identify a boat, this group often has ideas on what to check - steel tanks for example.
Good luck
Peter