What i would like to know, is it worth it to upgrade from sidewinder to eagle very early on?
Eagle first, highly fitted it's an often underestimated killer, good for bounty hunting smaller ships.
When you've got like a million spare cash, go for a viper and fit it accordingly.
Once you flew a well fitted Viper you won't go back. Screw the overrated Cobra. Everyone's flying that boring all-rounder but if you wanna do bounty hunting, go for the Viper.
My advice at least.
However, both Viper and Eagle cap out at class 2 weapons, meaning they will have similar power draws. But the Eagle can only fit class 2 power plant, which means you will have less juice to play with when outfitting your ship. Which also means to get maximum effect out of your Eagle you will need a high grade power plant A2 or B2, they cost a hefty amount of credits.