New Luggage/Suitcase?

Question

Im a 14 year old. I want a new suitcase for August 10th. I live in the uk.

we got the basic's out of the way then lol

Last year I wen't to tenerife, This year I'm going to Ibiza. When im in a airport I get really bad look's from people :( because I've got a pink suitcase. I also don't think that it's practical anymore.

This is my old one

http://www.argos.co.uk/static/Product/partNumber/2861625/Trail/searchtext%3ELUGAGE.htm

This is the one I want

http://www.argos.co.uk/static/Product/partNumber/2861986/Trail/searchtext%3ELUGAGE.htm

Do you think that the second one will be to big/small for me?

The first one was VERY big and I could get a lot of stuff in it. This year I want to take less incase it gets lost. Should I go for the 28 black or 24? I want it to fit all my stuff in.