Anywhere you go with your mates on a lads holiday you will have fun.
£50 per day would be more than enough I would suggest, a little more if you do stuff in the day.
Being 17 won't matter at all in terms of ID, not required anywhere you will be going.
Malia, Zante, Magaluf will most probably fit your requirements. I have been to Sunny Beach in 2011 and it was fun, and Albufeira in Portugal which was a bit of a toned down version of the aforementioned (which is what we were after). Far fewer British lads in Portugal as well.
And the more of you that go the better!