You're right, the style of dash in that car unfortunately makes it pretty much impossible to put a double-DIN deck in without custom work. The kit that we normally use in those cars replaces the pocket below the radio/climate control assembly and looks like this:
The kit retails for $49.99 and comes with everything you need for the deck install. We're in a transitional phase with car audio where a lot of our products are being pushed to clear to make room for the new models coming in, so store stock is a little sketchy right now.
For a deck, if you can get your hands on a Pioneer DEH-6300UB, that would be my recommendation. They're priced at $149.95 currently, which is a good deal for the features you get. This deck supports full iPod/iPhone control, two pairs of pre-outs (one can be used for dedicated sub control, which is good) and colour-shifting backlights so you can match the colours to the factory illumination.
For amp and sub I would pair up an MTX JH300 (on sale right now for $249, regular $299 when the sale ends) with the MTX dual 10" Sledgehammer box (on sale for $349, regular $399). Those subs will take more power, but you'll be spending about $100 more on the JH600 to bring them to their full potential. Lastly, you'll need an amp install kit, and depending on the quality of wire you're looking for they run from $49 and up. This is a good quality mid-level system, but you can go cheaper, and you can definitely go more expensive if you want.
Installation-wise, expect to spend about $69 on the deck install and $99 on the amp/sub install. There may be extra parts/labour involved depending on the vehicle, but your installer will give you a more accurate quote in-store. Hope this gives you an idea! Cheers.
