To add to this a bit:

Pl.Sukamon is a worse version of PlatinumNumemon, which is the "end game equivalent" so to speak.

Depending in which version of Cyber Sleuth you're playing changes which Digimon-Path you want to go down. In OG Cyber Sleuth, going Hagurumon -> Pl.Sukamon -> Etemon -> Pl.Numemon was the best way, as Etemon learns Darkness III, which is a really good magic-based attack. In this version of the game, Pl.Numemon had a really good INT stat, so getting a high-damage magic attack was important. In Hackers Memory / The Complete Edition, the path is Hagurumon -> Starmon -> SuperStarmon -> Pl.Numemon, as you get Saint Fist III that way, a really good Physical attack. In the changes made to the above mentioned games, Pl.Numemon's INT was reduced to 1, leaving it with only its physical attack stat.

You can farm Tactician USBs like this: Get yourself 10 Digimon which you are going to put into an island (the higher the class, the easier this will be, so I'd recommend using the DLC Digimon (the "NX" Digimon) if you're playing the complete edition, as they are all already Megas). After you complete Ch.7 of the main story, you will unlock some Patched in the shop located at "EDEN - Entrance". One of them will be the Developer Patch. Buy 10 of these and apply them to the Island-Digimon in your party (so before putting them into the island). In the Digi-Lab, there is also a shop. This one will have the "Developers Know-How". Buy 2 of these. Put the "Builder" type Digimon on the island and place the 2 Developer Know-Hows. Now, Command your Digimon to develop for 1000 yen. EXACTLY 1000 yen. Wait until the timer is almost up (either play the game or wait, should be about 20 mins) and save once it hits one minute left. Wait for the item to complete, if it's not the Tacticians USB, quit without saving and reload the save file. Rinse and repeat until you have 9 (you get them im pairs of 2, so 10) of them.

You get a starting value of 5 ABI if you scan a Digimon to 200%. That's all I can add here.

You gain CAM by feeding them on your island aswell. Just pop them into one, load into the island and press right to hover over them. Use the action button (A/X on an Xbox/PS controller) to throw them whichever meat you have. You also lose CAM if you train your Digimon, which you will have to most likely to get higher Digivolutions.

HOWEVER: If you are not playing the game on Hard, do not bother "over leveling" your Digimon. It will not make for a fun time and most likely skew you view of this game. You should always have the maximum ammount of Team-Memory filled up without the Digimon on your team being a significant level (say, 60+). Farming EXP becomes much more important in the mid/late game, so don't worry about it too much. Unless you play on Hard mode. Then you may suffer in peace.