Just some ideas off the top of head (more personal advice than choosing a site):
1) Aim for a site that has a 40-45 work week (like VA or State facilities). This makes for a more manageable personal life.
2) Finish (or be as close to finish, i.e., recruit all your participants, write as many chapters as you can, etc.....better to just finish) your dissertation PRIOR to internship b/c with family/kids and intensity of internship, poor dissertation ends up falling by the wayside.
3) Reach out for support when you need. I'm an older student with 4 kids under 12, and I have a tendency to just do everything myself without asking for help. I've realized it's better to just suck it up and ask for help when I need (from family member, friends, classmates, fellow interns), like asking my spouse for a night out w/ friends, or having our nanny stay late for a date night w/ my spouse. Self-care is always important, especially when you are busy beyond belief.
4) Make sure you have a good heart-to-heart w/ your spouse/significant other to "prepare" him/her for internship year. But still, I realize all the pre-planning can still fizzle away in the moment. I have my husband listed as primary contact for my kids' school during my internship year (as I have always been the first one called and will be again after this year), but there's a lot of drama that goes on during the day and I'm in much better a position to deal with family/kid drama at home rather than at work, when my next patient needs to be seen in 5 minutes. And don't forget date night w/ your spouse...I find it necessary to stay connected with mine b/c most of our conversations are about the kids when we're both SUPER-BUSY during the week.
5) Regarding more clinical sites vs research sites: Program brochures, internship open house, and interviews will all clarify that. I've always been a research-focused clinician but I knew that I needed my internship to be more clinically-based to save for a working parent's attention span and the fact that I intend to get as many pubs out of my own independent research as possible (have stayed part of close-knit research teams from former positions). So I positioned it during interviews as "I'm excited about his internship program's strengths and I'm fully aware that a limitation will be less research, which I'm okay with for this next year as I'll be publishing work on my dissertation and past research." Interviewers liked hearing this. This way I wasn't like I hate research (which I don't but in case you do), just give me more clinical training (which is what sites do NOT want to hear).
6) One bonus is finding sites that offer post-docs to current interns. Mine does not, so I had to spend a significant amount of time debating post-internship plans, where it would've been nice to just flow into a position already available to me. (This helps towards licensure by satisfying necessary hours to sit for your state's licensing exam.) Life does not let up, so it may help with stability, post-internship...and I'm always planning out the next strategic move anyway.
7) Lastly, try to make your research interests broad, with a specific focus related to your ideas (even though you are not aiming for a research site, you still want to show your proficiency and if the site is truly awesome, they will be incorporating research/evidence-based treatments in your training paradigm and didactics). For example, my research focus is "trauma" which fits well with all the sites I interviewed with (as it should). Your's may be working with adolescences, severely mentally ill, mood disorders, personality disorders, etc. Highlight the population and/or the broad interest, as it fits with your desired 40hr/week sites.
Dare I mention again...finish that dissertation.
It'll help your chances at 'picking and choosing' the site that you like the most (because that site has to LOVE you too).
Good luck!