Fygee, listen to Sapote.
Plant seeds from the most vigorous varieties like sapote said Peach cobbler .
I propose Dupois Saigon i have a 2 year old seedling uncovered growing in our 117 degree heat..sun pretty much all day. It is however at my friends home that has flood irrigation every 2 weeks so im sure that helps. This seedling was uncovered all last summer also. The only mango i never had to cover in the summer. Only covered when we had a threat of frost. I just started dumping a 5 Gal Bucket of EDDHA iron on my mangoes this year and they perk up /green up and love it. In between also i give them a 5 gal bucket liquid Fish and kelp along with mulch and that is it. My Dupois Saigon seedling leaves are upright green big and non-droopy.
I am on the hunt now for Peach Cobbler seeds and cac and also more Dupois seeds / anything real vigorous to bring back to AZ when i head to Florida in a few days.
Plant seeds and forget about those grafted trees...i killed too many to tell.
I know it takes longer but you will be rewarded with a strong tree most likely that can take the severe elements we share.
I know of a lady here in Arizona that has maybe 12-15 seedling trees 20-25 ft tall that have been thriving for years ..that bear small sweet semi fiborous mangoes. She lives near the Mountains/ hiking trails
Her mother planted a Mango seed from Safeway supermarket 20 or so years ago and she just continued planting the seeds from that mother tree...all the fruits from the trees are the same and she does not want to graft.
Practice patience and plant seeds

Graft later after 4-5 years.