The Harvester compares more with TBAC 30 PS. The Harvester is a 9" can, but really only has a 7" baffle stack as the last 2" are a muzzle brake and the 30PS is a 7" suppressor - weight difference between the two is a couple ounces. Sound wise the Harvester is very similar to the TBAC 30PS. Both are pleasant to shoot on a low volume cartridge. The 30P-1 is the same length as a Harvester, but has a 2" longer baffle stack. It is noticeably quieter to my ears, the difference becomes very evident when the suppressors are run on a magnum caliber.
If this is your first suppressor, I would push you towards the 30 P-1. I personally like to run the 30 brake attach TBAC suppressors, they just give you a lot more versatility to mount the suppressor to different rifle platforms (think different thread pitched rifles).
I am a TBAC and Silencerco dealer and have the 30P-1, PS, PSS, BA, BAS and Harvester in stock. I also have some of the CB cans headed my way. Pricing right now is as good as you will ever see a TBAC for. Shoot me a PM if you would like me to quote you a price on any of the suppressors.