I have an HK94 that I have my form one to SBR. Inaddition to the SBR I was going to get a paddle mag release installed. I know that the bolt has to be altered for the sear pack that I hope to eventually acquire. What other modifications can I get/should I get at this time to cut down what I will need to do in the future? I do not have the registered sear pack or the form so I want to be sure that any modifications are compliant with the law.