Welcome to the Fashion Spot, nikita27!
Those 2 things require vastly different educations and skills, from what I have seen. And no course or degree will propell you into the industry automatically ... it's way too competitive. It will depend on everything you bring to the table, education, internships, working experience and connections (this is a huge one).
Fashion design really will take a 4 years course because it's a very hands on thing that can't just be learned in a book ... it takes practice to develop the skills you will need in the work place. In addition to studying about fashion, you have to learn how to sew, make and cut patterns, drape, illustrate and all that technical stuff you will need to be able to do,to be hired by a fashion line.
There are thousands of recent graduates that will be competing with you for every job ... because being a fashion designer is considered a "glamour" field (although it really isn't.)... and they all will have 4 year degrees and some experience under thier belts, by interning and using connections. The grad with the best credentials and experience has the best chance of getting that low level job at a fashion house or even at a company like the GAP.
Marketing ... is marketing. There really is no such thing as a good "fashion marketing" course of study ... it's just all marketing ... so that is where you should focus your education. It requires good business and math skills and being in IT, you probably already have some of that going for you. Your training/education in marketing works for all fields, even autos, hamburgers, soap ... and fashion. But if you already have some solid experience in marketing, that might allow you to make the transition to working for a fashion line or retail company in their marketing dept. while you study a night or something.
We have threads on each of these occupations and lots more of interest here. In addition, if they mention any particular school that interests you, you may search by that school's name ... we probably have a thread on it, too.
I have done an Advanced Seach for you (searching by thread titles in this Careers forum) and have found these:
Fashion Marketing
Breaking Into the Fashion Industry
Education to Become a Designer: Is a Degree Necessary? Can I Do Individualized Study?
Give me some advice for becoming a designer?
how do i know if i'm 'good enough' for fashion design?
I want to Work for a Designer ... How Can I Make this Happen?
can you handle it? being a fashion designer *wwd article
And for more ideas about various other fashion careers (and we have threads on most of these ideas, too):
What Career for Me ... if I Can'tSew/ Make Patterns/Draw, Etc.?
Searching for My Perfect Fashion Career - HELP!!