dont go the way buying couple handles and set of tips you find that it is quite annoying exchanging them :)
you really need just few hexdrivers - usually 1.5.2.2.5 and sometimes 3mm or sililar SAE sizes if you own Losi or AE truck plus one philips and one flat screw driver.
Radek
V4 D8 - RX8, XERUN 4168SD
F1-09 - Tekin RS Pro, 17.5t Redline, 2S LiPo
Sakura Zero S - LRP, Saturn 20T, 2S LiPo
*EX-10 Eurus*