You are thinking too much!
Read, choose the most common processes on the board, read, ....learn by reading, not by asking.
Hoke is the basis. Hoke is 10%. The other 90% is the forum. Read both.
You do not need any chemicals, as long as you have such questions!
Dissolving tin in nitric is nonsense. To make stannous chloride the tin has to be dissolved in HCl, not HNO3! Tin and HNO3 gives insoluble metastannic acid, - something we mostly avoid, because it makes extra work and things more difficult.
If you absolutely want to use pure tin, you can filter off your metastannic acid, wash it with boiling water, incinerate it and redissolve it in HCl.
But:
Lead and copper in tin alloys are no problem for making a working stannous chloride test solution. If you have got solids in your test solution, you can decant the clear solution. Even silver can be removed this way. Add a piece of tin to make the solution more stable. Use a standard gold solution to check the test solution each time before using it.
As you can read in every second thread in this forum, SMB is fine with both AR and HCL/NaClO(chlorox). For deeper information, what happens,read the following thread:
http://goldrefiningforum.com/~goldrefi/phpBB3/viewtopic.php?f=37&t=13278