Mally is right, just put those attributes into the search filter. Start with all the attributes at 15 and assistant filter out unrealistic targets (if you still have your old AM) and downscale if you dont get any results.
You can also try selecting 5/6 attributes to match, although this might give him a glaring weakness.
Personally I change the ratings on what I find most important. I like to have an assistant manager with high judging player ability, so I can use him to give me a decent opinion on who should play etc. Discipline, Determination, and Motivation are probably the most important stats for coaching, but I choose to lower them because it's more important to me that my AM can offer me some insight into my players, and tactics. So tactical knowledge and man management are important, because he can offer you help with opposition instructions and team talks etc
So I normally start with search filter of:
JPA: 15
Tactical Knowledge: 15
JPP: 12
Man Management: 12
Determination: 10
Level of Discipline: 10
And then depending on the club, I use the adjust attribute up/down buttons, until I get a small list, then chose from there.
If you can't find anyone you like, just offer someone a one year contract so you can do the same next year when you have more rep. If you find someone you like, long contracts are good, because the longer your AM has been at your club, the more help he will be.
One last thing to take into account is that the best AM's are players who have played for you, because their tactics will be heavily influenced by you, and thus wont differ from you much. The best AM I've ever had was Francesco Cozza for San Marino, his stats weren't all that, but he pretty much always did what I wanted him to.
Hope that helps, sorry for rambling