Where to buy buds for chip bud grafting?

I have 25 apple rootstock (EMLA 7) and 20 plum rootstock (Myrobalan). I planted them this spring and am wondering if anyone knows where I can purchase new growth scions for end of summer chip bud grafting? I’m sure it’s not really a thing since they would be hard to keep alive during shipping and I know I’m running out of time to get them healed before first frost (zone 5b, Colorado) but I’m hopeful.  
I’ve got a local lead on apricots so really I’m looking for plums and apples. I had some success with my whip and tongue grafting apricots onto the plum rootstock this spring but I’m hoping I’ll have more success with chip bud grafting.
I planted my orchard last year with 3-5 year old trees but the grasshoppers devastated my apples and Italian plums. My hope was to graft the new growth off of them this year but growth was limited and I don’t want to stress them out any more by removing what little material the grasshoppers left. I have Surecrop, Liberty, Winesap, Honeycrisp, and Fireside growing in the apple orchard and a plan to protect them from the grasshoppers next year. The guinnea hens just couldn’t keep up with the grasshopper load this year.
Any tips on sourcing late summer scions to harvest buds would be greatly appreciated. I might just have to go to some local parks and do some guerrilla pruning

I could not find anything on the forum about chip bud grafting,

I thought I would give your topic a little bump with these videos that might be of interest to other folks:

Thank you! I was able to gather some apricot buds over the weekend. I was just getting ready to contact a local orchard to see if I could gather some apple buds as I’ve had no luck reaching out on social media. I attached some pictures of my apricot grafting I did over the weekend. It’s a waiting game but is definitely worth it just for the joy of making a new tree!