If I am not mistaken as far as visiting out of state you need to call the Highway patrol or state level police and make sure 1st that both items are legal and let them know you will be visiting with them. If you move to a different state you need to send in paperwork to let the ATF know that the gun is in a different state. If I am wrong I am sure sombody will correct me.
I did a SBR build using a 10.5 inch barrel and I am waiting on the form 4 back for the suppressor. I got the 7inch can from SAS so our overall lentgh would be about the same. I went with the 7 inch because it uses a flash hider adapter and the shorter one goes directly onto the barrel. I have 2 ARs and want the option of using it on each. I am also going to mail SAS my Encore 22-250 barrel and have them turn it down to fit the supressor also. You got to love multi-taskers.
I am also pretty sure that you have to send in 2 different checks. I dont know if you are going to build the SBR or buy one. If you are building the SBR the paperwork will go through quicker because you wont have to wait on the SBR to be transfered to your dealer unless he already has it in stock. It took close to a month for mine just for my paperwork to transfe from SAS to my dealer. You can not send in the form 4 to the ATF until your dealer gets the itme in hand. You can go ahead and send it in for your CLEO signature though and have everything ready. That is what I did. If you are building the SBR then you do a form 1 and it gets mailed to a different address than the form 4 for the transfer.
After going through all of the trouble with mine I would spend the money up front and go ahead and get a trust. This should also speed up the proicess because you will not be waiting on fingerprints to come back from the FBI for either item. It took almost 2 months just for my fingerprints. Now I have decided to get a trust and I will be stuck doing another form 4 on each item moving them into the trust and it will end up costing me an extra $400 in the long run.