All three are fine guns, but I personally would lean towards one of the revolvers because I have a bit more faith in the .38 Special than I do in 9x18 Makarov in terms of effectiveness. Even if limited to non-hollowpoint bullets (which, IIRC, you are due to the laws of your country), the .38 Special offers more efficient and effective bullet designs than 9x18 does.
With the 9x18 you'd pretty much be limited to round-nose FMJ which is one of the least effective bullet types available. Not only will you get no expansion whatsoever, but the rounded shape will create a smaller-than-caliber wound track because it will stretch tissue rather than crush or tear it. With the .38 Special, you can use a bullet with a sharper cutting shoulder like a semi-wadcutter or, better yet, a full wadcutter that will punch a full-diameter "cookie cutter" type hole and, if the lead is soft enough, may even give you some moderate expansion/deformation.
While I know that your selection and budget is limited, you might keep an eye out for a used S&W K-Frame like the models 10, 12, 15, 64, or 67. These will offer a six-shot cylinder like your Astra did and, here in the U.S., they can often be found for the same price or less than the all-steel J-Frames like the 640 (the prevalence of concealed carry laws here creates more demand for the smaller revolvers).
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