The weapons you speak of are members of the HK MP5 family, and all of them are considered machine guns. Thus, you either legally qualify for a Class III license, and spend between $12 & 16
thousand dollars on such a weapon
(Example - Link)........or you move on to....
An HK 94, which is as close to an MP5 as you can get in a semi-automatic weapon. $3 - 4 thousands for a nice pre-1994 one. The sunsetting of the AWB has no impact on any of these weapons because they aren't made in the states.....so they still command a premium among collectors.
There are some domestic knock-offs of these guns. First one NOT to waste money on is anything made by a company called "Special Weapons". The owner, Todd, is well known to be a 1st class cocksucker and his product is often suspect as far as quality goes.
My suggestion, in most peoples financial ballpark is an HK clone from Ohio Rapid Fire.
Ohio Rapiod Fire HK Collection.........(Link)Not a real HK, but reports seem to indicate that these are well made, and will satisfy most peoples needs. Also, the barrel length of the weapons you originally mentioned are considerably shorter than the 16" rule, thus making them, if available/affordable in the first place, as an SBR, short barreled rifle. The same legal catagory as a machine gun.....even in semi-auto.
I have no idea what the lagalities in IN are for Class III weapons or SBR's, but even if legal, you'll jump through some serious hoops and pay a $200 tax stamp just to qualify to own one. Anything full-auto/select fire or having a barrel shorter than 16" will put you in this legal window.