it looks like you are enthralled with semi autos. there are much better out there. how about a remmy 24 or 241, that is a takedown model? how about a 241 shorts only model, that fires nothing but tiny quiet shorts, and can even do it with CB shorts? mine does. how about a remmy 550, with the famous Carbine William's floating chamber design, same as in the 30 carbine? how about a nice remmy 552 speedmaster, which in one tube, can alternately fire short, long, and long rifle, and do it with ease, and hold about 20 to 25 short rounds in one tube? that's just for the remmy's. How about a marlin 70 papoose, or papoose HC? which means, came with a high capacity mag? how about the old little browning take downs, which dropped empty cases straight down?
I never thought much of the gsg models, and parts for repair will be scarce, they are being sued out of business. plus the ' one screw holds everything in place forward of the receiver' design, would have me a bit worried.
How about a nice new remmy 597, about 150 bucks, then put together 2 side by side 30 rounder remmy mags. then go over to rimfirecentral, read the stickies at the top of the 597 page, to get it running right, pay 20 bucks for each new mag, then say a red dot, or grean laser. You will now have spent less than 300 bucks, on a semi that holds 60 rounds at 1 time; and the 597 aint going anywhere!!!
armscor has been doing an AR and an AK design for about 30 years now, and they are reliable, and cheaper than the gsg; also Jaeger Armii from italy has been doing some fantastic ar's and ak's for a while now, and are still cheaper than the gsg. their ak in 22 mag, is a work of art and reliable; hard to do anything in 22 mag, and semi auto, and use the word reliable with it.
And I hate to say it, but a ruger 10.22 or a ruger charger/ 10.22 pistol, with extended mags, i would take over a gsg. I just think they are overpriced, and are going bye-bye, and they will break down, and you will not be able to get parts for one. So if you get one, you really
better get two. And don't get the colt umarex either.
Oh yeah, hamerlii makes a superthick , heavy 22 sporter semi auto, with firefly sights; rifle is very heavy and substantial, and it is made with the 17 round tube. Which american companies cannot
make, but the hamerlii version has one. and they are under 200 bucks as well.
What you need to look for on your marlins as well, is one made between 85' and 88'. these are the grails of the mod 60's. Why? because they not only had the little lever on the right side of the trigger guard, which is a last shot bolt hold open lever, but they were also still made with the 17/18 round tube. so for 3 year period, the mod 60 had a 22 inch bbl, Last shot bho lever, and a tube which could hold 17 or 18 rounds. this is what you want.
If limited to your list, get the sig.
Mine is a blast to shoot, and while the OP has other .22s to fill the same roll, I have found this to be the most fun .22lr that I have owned or played with, and he said he wants to eventually get one anyway. So if that is the case, now is the time, they'll be no more [imported].
can you say Buckshot? 
