wow, thats a lotta drones, great fluff for them, it really sounds like something the tau would do, but are u really gonna fight with it, or just show it off, cause we both no it would not do so great, but if u added some special rules (eg that the drones were stronger than normal drones) then it might just work
Well, it really depends, on what type of army you want. Warhammer 40k offers many different options.
The Tau are a relatively new race, and offer lots of firepower, and speed. They are horrible in Close Combat, but can be very effective if used correctly. The Tau also have the Kroot, which are opposite to the Tau, as they have bad shooting, but good Close Combat skills.
If you want weird and creepy go Tyranid (can get very confusing, they are large close combat oriented monsters)
If you want EVIL, go Chaos Space Marine (high armor save, good in close combat, and good at shooting, but fight in relatively small numbers), or you can pick Dark Eldar (like dark elves of fantasy, they are evil, good at shooting, but low armor)
If you want Human go with Imperial Gaurd (low armor, great tanks, and fight in large numbers), or Space Marines (which are like chaos space marines, but no as evil).
If you like good, go with Eldar (like high elves of fantasy, fast, good shooting, low armor)
If you like machines, then go with Necrons (they are machines, and have good armor, and lots of special rules)