Several helicopter flight schools now offer integrated training courses offering theory and flight training on a full time basis. Beyond this, some schools also offer part time (Eg. 2-3 nights a week) theory courses.
If you’d like to complete your theory with the same school that you complete your flight training, my best advice is to make a few calls and ask them what packages they can offer.
Self Paced Courses
This is how I completed my theory. While it’s definitely achievable, it’s a fairly solid commitment!