My gisela-6 rootstocks coming from same place arrived as was advertised in the catalog. 3/16 caliper and the advise listed to not graft it for one year. In mine I could tell they were cuttings that had recently been rooted and all the reserves had gone onto pushing roots. When carbs are depleted then time is necessary to ramp the carbs back prior to grafting. Each of them may still be budded this year unless you can't find wood prepared during this 2019 growing season to procure buds from. Similar with your seedling peach. Also the dormant peach or cherry-wood scions are often not reserved for use the right way.

As for the pear, I don't know what the pear looks like to know which part is best grafted, nor what the size of your scionwood is. I am also afraid a first time grafter would perform unsafely. Even being a retired electrician so experienced shaving insulation of copper wires with a knife did lightly cut my finger on light duty grafting in one of the positions of HOS volunteer last month. So if you want me to take a picture of a 20 dollar tool that can make a straight slant cut on up to 5/16 inch scionwood for whip grafting then let me know you need it. 

Or if not maybe?? somebody else has a better eye on how to answer your points. Maybe there is a budding shop too.

By the book of methods -the sweet cherry -the peach, neither listed for dormant grafting. The book footnoted other studies involving a high ebb of bacterial canker disease(s) being very high this time of year and they exist in the rootstock. But the fact that upon purchase these roots are treated responsibly (sprayed sheltered etc) then you should be free of all that. Contiue that responsibilty and shelter them now and after grafting. Or grow them outside of anywhere west of the Cascades (not within). 

Some peaches here are better such as Frost peach. Rainier is the better choice for gisela-6 based on recent experience in Oregon. Cultivars play a big factor anywhere west. After several years placed in the permanent location they can become strong enough then to be grafted to other cultivars. Gisela-6, more than the other gisela series, "is" the root of most worry on a choice other than Rainier so far. Purvis Nursery (whom I have no affiliation) lists 'Redlac' cherrywood scions and possibly Rainier. Redlac is a red sport of Rainier if you were to ignore some mistakes in the Redlac patent. So it will not cross pollinate to Rainier. Purvis nursery in Idaho is very dry so wood infected with bacteria is extremely rare. His wood is stored at the proper low temperatures.

If you want to try budding then I want to tell you a little true story. ...Around 8 years ago in the latter half of April I had some correspondence with a peach and plum breeder located in Minnesota. Each of us decided we wanted some of the very large plums that were developed by the ARS. Since the person in Minnesota was well established the department of ARS let me pick up his scions from California. So I drove down to Parlier CA and back with bunches of current season's budwood in a cooler. I sent most from PDX to Minnestota in regular mail when they were reported to have sat in his hot mailbox for hours before he found them. He chip budded. Mine were "T" budded. A few weeks later I got a report from him they were growing. Then a year after that he wrote up a nice article on "spring budding" since his winter survival had been far better than prior attemps of summer budding! He also encouraged other greenhouse growers in writing on how and why to change to spring. 🙂

The method is an adaption of spring grafting taken from "Principles of Plant Propagation" by Hartmann & Kester and adapted by him. The version change in Minnesota was by Dave, an ex football player now deceased but is essentially my adapted method that he authored. So now I will PM you my email so that I can find out your email in case you want me to send you our file. 

The article fails include any the above fore-warnings but please remember them. Plums are easier. Peaches are listed as a root for plum when you use a compatability chart. Peaches can also serve cherry per some other discussiins out there with 'adara' interstems (double grafting).

I do have some dormant scions of cherry in heathy shape due to it being collected from a durable flowering Japanese cherry. This I did for my own gisela-6 interstems so that I can make up my mind about cultivars down the road but I can spare you a couple scions. 

I have no affiliation with any named companies above and I wish you luck.

...PM sent.