Hey man. I've 24 and have been using Rogaine and finasteride for over two years now, and during that time have regrown and maintained a good amount of hair. Like you, I was faced with two choices when I noticed my hair thinning, going with the Jason Statham look as you put it, or getting on treatments and keeping what I had. I chose the second, after all, who doesn't look better with hair?
First off, Rogaine is a hair growth stimulant, and does not clear the scalp of DHT. It doesn't affect scalp or internal DHT levels at all, nor does it interfere with the fundamental balding process. It was discovered to regrow hair by accident during the 1980s and its mechanisms in doing so are still not really understood. It will, however, regrow a great deal of hair in the majority of cases. Your regrowth from it, as with any hairloss product, with cease upon discontinuation. Since it's a topical, it's an extremely safe treatment and no sides have ever been documented that I know of.
While I have no experience with dutasteride, I'm familiar with the drug. Basically, it's a more potent version of finasteride. Both drugs inhibit internal DHT levels (finasteride-80%, dutasteride-90%). In clinical studies, 85% of those using finasteride had more or equal the amount of hair they had five years after beginning treatment. I would imagine it would be even higher for dutasteride. In that finasteride study, only 2% of men experience side effects, all of which went away after discontinuing usage of the drug. I believe it was 10% range in the dutasteride study but I don't have that study in front of me. Dutasteride, while the stronger of the two, should only be used in cases of severe hairloss or if finasteride is becoming less effective for you. I plan on switching to it once the latter occurs.
So what should you do? If your hairloss isn't too bad (which it doesnt sound like it is) and you just want to maintain what you have and maybe get some slight regrowth, your best bet is to just take 1mg of finasteride once a day. Applying Rogaine to your scalp once or twice a day can be a royal pain in the ass and I only recommend you use it with finasteride if you really want extra regrowth. When the two treatments are used together, in conjuction with a DHT scalp lowering shampoo like nizoral 2-3 times a week, you shouldnt worry about going bald for well over a decade unless your male pattern baldness is ultra agressive. Good luck.