eFile is no longer available since 41F went into effect.
As for a Form 1 vs. a commercial suppressor, I would say that for the first one, a commercial suppressor would be better for you. I would also suggest a direct thread can as it will be being used on hunting rifles so a quick change over won't be necessary.
My recommendation would be a SilencerCo Harvester 30. I have one that I use on my .243 (Ruger American) and on my 6.8 SPC AR-15. It works very well and is very light. It won't break the bank either. Capitol Armory has it for $545 so you are looking at less than $800 with the tax stamp.
As for time, it is a long wait right now as they are still working through the backlog from the massive amount of Forms that were put in just before 41F went into effect in July. That being said, once that pile is complete, I would suspect that it will go down to 2-3 months.