I'm going to use the Epson Artisan 1430 inkjet printer, which uses 6 inks, for my project to do sublimation. Will this have any effect on the colour or resolution of my image?
The CMYK has nothing to do to resolution.
It does not "damage" the color either. Actually there is nothing you cand do but send it as RGB or CMYK.
An Inkjet printer makes its own internal transformation, in this case if the ammount of cyan or magenta is low for light colors, pastel ones, simply it uses the light color, and if you need a more vivid one it uses the normal cartridge. In this type of 6 color printer the improvement is on the light colors, where you could tend to see the dots of thoose 2 inks.
You just need to do some print tests before any project. Embed the necesary profiles.