Form factor:
1) Do you use the numeric keypad often? For some people it is a must-have, others people never use it.
2) Do you use the arrow keys a lot, nav cluster? (or are you a VI freak who uses JKLM to move the cursor?)
3) Do you use an IDE that requires the function keys?
If your answer is No all three above, then you could use a 60% keyboard that has only the main cluster.
If you don't use a numeric keypad then I would suggest a "tenkeyless" because then you could place the mouse closer to the centre - which is better for avoiding problems in your mouse arm in the long run.
Layout: Many programmers prefer ANSI layout because of how many programming symbols are readily available, but an ANSI-layout keyboard can be difficult if you want to use a European ISO layout (vertical Enter key) because it is one key short compared to ISO.
You can use US-ANSI layout with any keyboard - you only need to change it in the operating system you use because the mapping form scancode to symbol is in the operating system. I know that at least Windows do allow quick switching between different layouts.
If you buy a keyboard from outside the EU then you are likely to get to pay import taxes. But there are ANSI options for inside the EU: The Keyboard Company in the UK has several models available in ANSI for instance. ANSI is also used in the Netherlands.
Me, I write C in Swedish layout - and the Alt Gr key gets a lot of use, but that is what I am used to.
Switches: I have programmed on Cherry MX Blue, Brown and Clear as well as on Topre. All of these are fine. Blue might not be popular in an open-plan office (although I have seen people use it.....)
I have tried Cherry MX Black, but I would not recommend it as it is a bit tiring.
Backlighting: Completely unnecessary for professionals who know how to type. I have been using a keyboard without any legends at all with no problem, and it shouldn't be a problem for you either.
Most backlit keycaps are translucent caps that have been painted with an opaque paint. The paint has very little texture and it will wear off with wear, leaving ugly glowing holes. High-quality keycaps of PBT, on the other hand, should last a lifetime. If you are going to hammer the keys for 8 hours a day, five days a week for five years (or so..) then quality matters.
Media keys: You can always remap existing keys, or a combo to a media key. For instance, I have Print Screen, Scroll Lock and Pause mapped to Previous track, Next track and Play/Pause.