I recently finished a Type IIA career out of 1st Flotilla, Wilhemshaven with SH3 Commander at 100%. I can honestly say I love that Type IIA to death as it has been the ultimate challenge to manage, crew wise and tactics wise. Some things to keep in mind: She can't go far at ahead standard so stay at ahead one third (I did most of my patrols at ahead slow to save diesel). When you start your career, enlist the maximum number of men on your boat, you'll need them!
I also suggest taking one Type II G7e in your loadout of five incase you run into an escort in calm seas or something. Install the 20mm flak gun on your bow is also highly recommended as you might consider going along the coastline for ships (and running into the Royal Air Force as well). So far, I have successfully made patrols lengthing from Wilhemshaven to Scapa Flow then all the way down to Dover along the coastline of the UK and back to Wilhemshaven. After my current career out of Lorient is done I am looking forward to starting another career in 1939 with my Type IIA. I hope this information helps you.