Getting back to OP's questions: I would avoid Mauser M93 and M95 actions and Chinese M98 copies. Swedish M96/M38 are OK. Just about any Mauser M98, Argentine 1909, Czech VZ24, FN, Mexican 1910, Interarms Mk X, Husqvarna, Oberndorf would work. I've had one Austrian Steyr that was too hard to drill.
Look for matching numbers, but if you are going to rebarrel a non-matching bolt will work. Avoid pitted receivers and bolt faces. Check the engaging faces of the bolt lugs for setback marks(avoid) and even wear. Make sure drilled surplus actions have the scope base holes in a straight line and spaced to match currently available scope bases. Look for cracks in the front ring...although cracked receivers are uncommon, not unheard of. Check for receiver straightness, sometimes rails get bent. Make sure the lip of the extractor is not chipped. Inspect altered bolt handle roots for complete welds and professional weld grinding/polishing.
Ludwig Olson and Jerry Kuhnhausen authored books on Mausers which are excellent sources of information.
