Re: detachable mags
What do you consider "inexpensive"?
There are multiple options, but none are what I would call cheap. Here are some of the better options, but they run $200+ and you'll need additional mags as well:
CDI - $284 (incl. 1 5rnd mag)
Badger - $325 (incl. 1 5rnd mag)
Seekins - $300 (can't remem. if the seekins kit comes with a mag or not)
Surgeon - $360 (incl. 1 5rnd mag)
H-S Prec. - $280 (inc. 1 4rnd mag)
I have personally used the CDI and Badger units, both of which are first-rate all the way in terms of quality, durability, and function. Of course...all of these come up for sale here on the Hide from time to time and you can save a little money over NIB pricing. Also, all but the H-S kit will require some inletting work on your stock to fit properly.