If all you want is stick mags, about the cheapest/easiest 9mm magwell to use is the UZI. $20 @ Centerfire for a stripped lower with mag catch. Can be used bare or buy/whittle a set of grips to make it look better. You will still have to cut to fit and weld in, possibly fabricate a feed ramp as well.
thats a really good idea and one I had not thought of. Yea you really dont want to go grinding on a barrel and all that crap it would look like Sh!T.IMI Uzi Grip (Stripped) Part #UZI-GRIP STRIPPED
Mags can be found used in the $12 range to new @ $20.
As far as lathe work goes, several people here do lathe work on bbls, it will cost some bucks but look and function a lot better than hand grinding.
If your going to do it do it right. read all the threads here in the last 5 years and then you will have a lot of knowledge. if you dont understand some thing then ask away there are no dumb questions when it comes to guns and safety. no one here will slam you for not knowing smething. they will slam you for wanting to do it half assed or un safe or ugly.
If an when you get ready for a barrel I and others can help for a resonable fee sometimes free if its some thing simple.