Panzerjäger, SdKfz 8 FlaK 18, etc. ...

[PatG]

Since the Germans were the kids with the cool toys, their OOB is packed with units that were never manufactured in any great numbers.

I can't speak to the German units - though apart from the 105mm all are standard AT guns.

Add core points? - Yup you can start with a platoon and work your way up to a battalion if you want to. (and get enough points)

Tank busting: The obvious choice would be the Russians with their SU- and JSU- series. The Americans are next with their dedicated tank destroyer doctrine - a lot more fragile than the Jags/SUs though.

Early Brits are "interesting" - 2 pounders kick butt on early German armour and come in portee versions. Japanese - the only tank busting you are going to do is with Gunjin carrying satchel charges.