For hard floors and pet hair a canister would be ideal. Henry vacuums have strong suction and large hepa bags, there are several sized from 160, 200, and 240. Henry 160 is a medium sized canister, the Henry 200 and Henry 240 actually use the same hepa bag but are bigger so the bag will hold more in them. If you want the lightest weight I'd stick to a Henry 160. The Henry 200 is large and has a longer cord, probably your goldilocks option. I think the Henry 240 is overkill. I'd also add a Wessel Werk RD285, it's a hard floor tool without a brushes that hair will get caught in, it will gulp up hair. Personally, I like the Wessel Werk Turn & Clean Brush, it does have brushes so you'll want to vacuum off the hair when you are done, but it has a ball joint that lets it swivel and turn better than other brushes.

Miele and Sebo also make great canister vacuums and have more local vacuum stores that sell and service them. You could look at the Sebo E1 Kombi or Miele C3 Calima.

Hope that helps.