Check your big box home improvement centers and patio furniture stores.
Go to the place where you bought the patio chair from, you should be able to order a replacement chair from there. If you cannot, try Home Hardware, Home Depot, or Canadian Tire.
Perfect Home patio swing model S05293 replacement parts can be found online. Auction sites, such as eBay, offer these parts.
I would think it is possible to buy only an umbrella for your patio set. Most patio sets, sold by stores, can order replacement parts for you, regardless of the color that piece may be. Check with the store to see if the manufacturer has a replacement umbrella.
Fabric top
http://www.servicesupportlink.com/umbrella-parts.html
Try D&JPatio.com
You should be able to find replacement parts for a patio swing model s05293 in 2 places. One is the store where the swing was purchased. The other is from the manufacturer of the swing.
Just because a patio umbrella is missing a part doesn't mean that is has to be thrown away, which is good news, since a good-quality patio umbrella can be expensive. It can also sometimes be difficult to find a new umbrella that matches an existing patio set. Many companies offer replacement parts for patio umbrellas, including replacement umbrella canopies and replacement umbrella frames; these parts are typically inexpensive and fairly easy to change.
Yes, you can get replacement cusions at most home goods stores. World Market is a good place.
Chair Care Patio Furniture Repair is your complete source for DIY outdoor patio furniture repair parts and supplies. Chair Care Patio offers custom made patio furniture cushions, replacement patio chair.
Depending on the size, many sites online sell replacement canopies. Startwith sites like www.marketunbrellasite.com or www.patio-umbrellas.com to see if they have your size in stock. Additionally you can try www.shadeusa.com or www.homedecorators.com