I had a LasDrop Gen II put on my 356 last year. I preferred it to PSS for the longer maintenance interval. You can find it at a variety of vendors. This is the size I ordered:
Gen II Shaft Seal for 1" Shaft, 1-3/4" Stern Tube, G-100-134
If you prefer the PSS version with the bellows, that's available on the store here:
@forsterp Welcome to the forum.
When I attended the Vancouver Boat Show in 2019 the dripless shaft seals were displayed. You could talk with the company rep and compare the two items. They might even offer a promotion.
Both units mentioned have a following. The PSS unit I believe has a longer history. As said it has a maintenance time frame that may be a concern.
Practical Sailor reviews preferred the PSS and Lasdrop GenII. Folks also recommend the Volvo. I have had the Lasdrop for a few years. I just prefer their design. Lots of threads on dripless seals. Even whether to switch over to one or not.
Had A PSS since 2006. Just replaced the bellow this year (2020) which still look and feels good. Not a drop of water for all these years. Can't use the LasDrop Gen II because it requires more space between the stern tube and the transmission. They works on the same principle.
I have used the PSS for years but the new ones may have a problem. The design has changed and the new style bellows may be prone to cracking. Tried to communicate my concerns with PSS, even sending a detailed letter and one old and one new design bellows displaying the differences and the cracking problem but never got a response. Followed up with telephone calls but still no response from PSS. Be careful.
I replaced my PSS seal on my 92 Hunter30, last year. The diameter of the shaft was 1 inch. The hardest part was breaking free the shaft from the transmission. Little brute force was used, but once moving the shaft slid back far enough to pull out the old unit and replace with the new. My old unit did not have the nipple for water to exit. With this new unit, I had to add a hose which goes to the bilge. Though the PSS instructions say to raise the hose to 3 (?) feet above the water line, I do not have that much room. Up to this point, it has not flushed out but I know under extreme power it will. Just something to keep in mind.