Would it be better for me to get composite resin or porcelain emax veneers? (Photo)

I would do neither at this point.  I see a bigger issue.  It looks as though you have an open bite in the front.  This is from tongue thrusting and likely an airway issue not allowing you to breathe though your nose.  I am willing to bet that you mouth breathe often, and likely wake in the morning with dry mouth.  This airway issue needs to be addressed or your bite will continue to change over a period of time.  I think you need to find three professionals to help.  You need a dentist that understands airway issues and has a good relationship with an ENT.  Have the airway evaluated by the ENT.  It may be time to have the tonsils and adenoids out.  After this, find an orthodontist that can close your bite back down to an ideal position.  For now, don't worry about veneers or composites.  You have bigger issues to deal with.  Good luck.  

Porcelain veneers is the best choice for 4 reasons.
1) Never change the color (you can drink coke, coffee and the color will be the same)
2) This material is more perfect, more natural and more aesthetic.
3) It is very resistant, you can eat what you want without difficulties.
4) This last  more than 15 years.
Composite veneers are a good material, but they need more maintenance because they change color, are less resistant and last between 5 and 7 years.
the most important thing is what the treatment you choose is minimally invasive for your natural tooth and this with a perfect adaptation.

Porcelain is always better than composite when it comes to veneers!!
Composite is a plastic material that dulls and discolors over time. Porcelain is a glass-like material that looks more like natural enamel, and is a lot stronger. Another advantage is that porcelain lasts a lot longer than composites. 
When preparing the teeth for both eMax and composite veneers, the tooth has to be etched which is a non-reversible process. In many cases, teeth need to be roughened up in-order to get composites to bond and adhere to the enamel.
Another option to consider is a conservative minimal or no-prep porcelain veneers. These next steps in veneer technology allow you to enhance your teeth without altering the enamel, and in many cases the veneers can be removed if desired. 
Either way, may sure your going to an expert cosmetic dentist who has good reviews and work that you like.