The Gatorskins will give long trouble free life. Apparently so will Paselas. BTD usually carries 14 or so types of 27" tires, though right now 5 or 6. Im sure the Covid boom has manufacturers making as many 700c as possible, filling the production line.
As well, the high nimber of people pulling the 27" 10 Speeds out of the garage has them in short supply.
Velomine is a good source of 27" built wheels. Got a pair with Quando sealed bearing hubs and Sun CR18 rims this year. Very happy with them.
https://www.biketiresdirect.com/search/27in-road-tires
https://www.velomine.com/index.php?main_page=index&cPath=235_243&zenid=a2ffisgh3qmual2gj7b9mf87p7