You could easily do it yourself.
1. Base coat (black or grey - I prefer grey)
2. Paint the panels the two shades of grey.
3. Apply black ink
4. Touch up panels with the original greys.
5. Add a little white/lighter shade of grey to the original greys and run your brush along the edges of the panels (highlighting). You can repeat this step as many times as you like. Once or twice is fine though.
For the Imperial symbols.
1. Grab some custom decal paper. I use Testors. Be sure to get the correct paper (laser or inkjet) to suit your printer.
2. Print design onto the paper.
3. Seal with a matte varnish (I use Testor's dullcote)
4. Paint the area of the model with gloss varnish to make a smooth surface.
5. (Optional) Micro set.
3. Apply decal.
4. (Optional) Apply and re-apply micro sol until happy. This softens the decal and lets it adhere/shape to the surface better.
5. Paint with gloss until you no longer see the decal seam.
Paint the whole model with matte varnish. Again, Testor's Dullcote is fantastic. 4-5 light coats is better than 1 heavy one. Paint the cockpit with the gloss varnish.
Super easy and you will get fantastic results. You really don't have to be a good painter to do this ship.