You have quite alot of work cut out for you.
Here are all the farm quests:
Holy type
- Lazy Tapirmon
- Lazy Starmon
- Lazy Monzaemon
Dragon type
- Cool Dinohumon
- Scared Growlmon
- Cool Veedramon
- Prissy MetalGreymon
- Lazy Megidramon (unlocks Shadow Abyss)
Aquan
- Scared Gomamon
- Cool Gwappamon
- Prissy Octomon
- Lazy ShogunGekomon
- Cool Vikemon (unlocks Shadow Abyss)
Bird type
- Lazy Saberdramon
- Wild Peckmon
- Cool Karatenmon
Also, do you have wifi and are you a Platinum tamer? You need to have accessed wifi at least once, you must be a platinum tamer, and you have to have beaten the Gaia Origin to gain the union quest: Legend Tamer Quest. You need to beat a:
Lotosmon lv.74, Dianamon Lv.82, and MirageGaogamon Lv.74 owned by Sayo.
GeoGreymon Lv.85, Gaogamon Lv.85, and Peckmon Lv.85 owned by 3 guys whos names I can't remember.
Rosemon Burst Mode Lv.90 and Ravemon Burst Mode lv.90 owned by Yoshino and Crier of Data Squad.
ShineGreymon Burst Mode Lv.90 and MirageGaogamon Burst Mode Lv.90 owned by Marcus and Thomas of Data Squad.
The last digimon and tamer are two you need to find out on your own. I will give you this information: Burst Counter and Full Repair Ts are you best friends in this fight.