You can find a drop through shiptotheborder.com My sister uses their drop in Niagara Falls and is satisfied (1 transaction). The thing with them is that it is an aggregator of many independent locations, so your services really depend on how good the Buffalo location is. Check hours to be sure you can get there, also watch charges carefully, they vary by location. Some will charge storage after x number of days. Maybe someone who has used the Buffalo location will chime in.
I use myusaddress but their only location is Ogdensburg NY. Have done many, many packages with them and am very satisfied with service and hours of operation (7 days/wk, extended evening hours hours). Note they also offer a "push it north" service (added cost), so it can be used to border clear and forward items to anywhere in Canada once they arrive at your US side address. The underlying company is a Canadian logistics company with warehouses in both Ogdensburg NY and Prescott ON. It is a great option for those in Eastern Ontario, or anywhere if you want them to handle the forwarding as well.