There are so many wonderful local needlepoint shops around the US, and several online.  Below are some of my favorites!   Shops marked with an asterisk (*) currently carry canvases from Halcyon House Designs.  
 
Erica Wilson
25 Main St
Nantucket, MA 02554
https://www.ericawilson.com
508.228.9881

Hingham Square Needlepoint
185 Lincoln St Suite 200A
Hingham, MA 02043
https://www.hinghamsquareneedlepoint.com
781.836.5200

Lycette Designs*
230 S County Rd, Suite A
Palm Beach, FL 33480
https://www.lycettedesigns.com
561.469.9155

Peacock Alley Needlepoint
452 Ada Dr SE, Suite 120
Ada, MI 49301
https://www.peacockalleyneedlepoint.com
616.682.9854

Stitch By Stitch Larchmont
1971 Palmer Ave
Larchmont, NY 10538
https://www.stitchbystitchneedlepoint.com/
914.834.1886

Stitches by the Sea
710 East Atlantic Ave
Delray Beach, FL 33483
https://stitchesbythesea.us
561.865.5775

The Needlepoint Clubhouse
11208 Manchester Rd
St. Louis, MO 63122
https://www.needlepointclubhouse.com/
314.432.2555

Threads Too*
795 River Rd
Fair Haven, NJ 07704
https://threads-too.myshopify.com
732.530.9092

Village Needlepoint
1 Bridge St
South Dartmouth, MA 02748
https://villageneedlepointpadanaram.com/
508.999.2477

West Village Knit & Needle
225 West 10th Street, Ground Floor
New York, New York 10014
https://www.wvknitandneedle.com
917.262.0121