Let me preface this by saying that a well done mil-surp sporter can be a true thing of beauty and a very rewarding project. A badly done sporter can be a money pit and the senseless destruction of a fine historical weapon.
Unless you've got a good friend who's a gunsmith willing to work cheap or free, or you already have your own gunsmithing tools; you'll do
far better for your money spent and the end results to build up a custom rifle on a Howa or Stevens action.
A Yugo M48 or a bare k98 action are going to be the only ones that can possibly make economic sense for sporterizing these days.
Doing things like bending the bolt handle, headspacing and installing a new barrel, drilling and tapping for scope mounts, fitting a more ergonomic and scope clearing safety, inletting and bedding a stock, etc. all require time and specialized tools.
My grandfather started the sporterization of this Carl Gustaf M96 but passed away before he completed it. He rebarreled it with a Douglas barrel, bent the bolt handle, and drilled and tapped it. I finished it with a cock-on-open conversion, Timney trigger, model 70-style safety, and synthetic stock. Someday I'll get it reblued and find a nicely figured wood stock for it.
There is
no way I could have gotten it to this point if I hadn't also inherited Grandad's milling machine, drill press, inletting tools, and tons of other stuff.
Please know what you're getting into before you start in on a fine old rifle with a hacksaw and arc welder.