the reason i say air is more suitable for a daily is because it doesnt take up as much space in the boot, you dont have to charge batteries (although there are ways around this for juice) and its cleaner if something goes pop..
FD's right, while you can do it on the cheap, spend the money upfront and it will save you in the long run, HOWEVER.. if you just want to get up and running spend the money on big-port bags and your mountings, plus a decent compressor.. valves can be brought on the cheap if you bide your time; i just sold 8 big-un's for £120
if you shop around on US ebay you could get 8 valves and a decent compressor for £200, tanks are pretty cheap, bags around £60 each as FD said, and the lines are negligable.. I reckon a fairly fast single comp system (viair450, 5 gal tank, 1/2" lines) should be do-able for under £500 if you hunt around and possibly less if you find a few cheeky ebay bargains (ie you might get some 2nd hand decent bags for £50 and a comp for £60 or 70)
Also, if you just want to get up and running for now, go with small lines and paddle valves.. that will get you low, but it will be v.slow (my first w123 merc ran 1/4" lines and paddle valves and took about 10sec to raise the front).. fit big port bags, small lines, paddle valves, small comp and you can probably be up and running for £250