For the U13 boy question, I would go DA and just deal with the commute. Being around other good players will really push him to improve, plus hopefully the training is good.
Being on the local club's A team will always be an option, and if he's in DA for a year and for some reason you don't like it, they will take him back with open arms. If the DA a fit, then stay with it. Not every kid as an opportunity to be in a DA program, so if your son has it, try it out for a year and see how it goes.
For the question about an '06 girl - which area teams / coaches would I like?
I believe Arlington Red & White are doing well in this age group. The coach must be doing something right.
I may have mentioned DC Stoddert before... Karen Kelser is working the U11/U12 age groups and she is a very good teacher of the game to both to players and other coaches. I have a lot of respect for her expertise.
Loudon looks good, this fellow Dan Raben (never heard his name before, but read his bio) seems to know what he's doing with Loudon Red, the top team. -
http://www.loudounsoccer.com/techstaff/ (scroll to bottom).
The loudon coaches for 06G Red, 06G Black, 06G White, and 06G Silver look pretty good on paper at least.
Mclean - nobody at U11 who I can really say the same track record of any of the people mentioned by name above. Who knows though, I haven't even seen the team in action.
SYA - CAROLYN RICE....If I had a daughter, I'd want her to play for Carolyn.
Bethesda - I think Sam Roos the daughter of Brad Roos. I'm sure she's been around soccer since age 1 and knows what she's doing.
SYC has Harry Okopu coaching the U11 girls, he is the technical director there.
That's about all that stands out to me at the moment.
Let's pretend commute distance is not a factor here - these would be my choices
1. SYA - Carolyn Rice, my #1 choice here.
2. Arlington - Team seems to be doing very, very well
3. Loudon - Quality age group staff coaches across the board, mutiple teams
4. DC Stoddert - Karen Kelser
5. Bethesda - Sam Roos, Bethesda has good girls teams every year
6. Mclean - Just because its McLean which traditionally is decent on the girls side
7. SYC - Technical Director is coaching the U11 girls