I think you should think about your study plan before you apply, that way you can determine if right now its even possible to accomodate 20+ hrs a week of studying into your busy life. You might decide to wait another year or something.
If you decide that now is the right time, then I would apply and start studying while you are waiting for the application to get approved, once approved you get a notice to select sections to take, then wait for a payment coupon, pay exam fees, wait for a notice to schedule (NTS), then once you get that you can actually schedule the exam.
I also would recommend only signing up for one or two sections per application, which means you have to pay another application fee to schedule the other two sections. Each NTS has an expiration date, so if you put 4 exams on once NTS, then you have to take all four in that time frame. Every state is different, in CA, each NTS expires after 9 months.
The cost of a review course is a factor, and one that I struggle with too. I finally just decided to approach it the same way i did student loans in college, its a necessary expense! and one that will pay for itself eventually. I told myself that I am worth the investment! I dont care if I have to put it on credit cards, i deserve this chance to get the CPA, and I know once i do it I can pay off the credit card in no time.
Also if you wait for a good sale, you can get really good deals. Lambers just did a 40% off all 4 sections deal.
Watch demos for Yaeger, Becker, Roger, Lambers. Personally, i like Roger's lecturing style best because he's funny and entertaining. Lots of people really like Yaeger's teaching style. So it all just depends.
Good luck!