Definitely invest in good flycasting instruction (it is cheap relative to the cost of the kit and means you can actually use it much more quickly). The casting qualification to look for in your instructor is the AAPGAI (check the magazines and also google for database of instructors by region).
If cost is not a big deal - then go for two rods; a long (10ft) Greys Streamflex for a number 4 line for nymphing and wetfly (and dry fly too) on rivers without tons of tree cover. Also get a shorter 8 and a half to 9 foot rod for dry fly and smaller/more overgrown streams (probably a number 4 again is a good compromise).
Match them with floating lines (I prefer drab colours, because even though against the pure sky all lines are black, when you fish beneath dark shaded vegetation, the fluorescent colours show up).
Take advantage of the passport schemes on the Dart and westcountry rivers (Angling 2000). These provide totally wild fishing and also fund the conservation of the rivers that are included in the schemes. There are more of these schemes springing up around the country:
Wild Trout Fishing
To put you on the right track with approaches I could plug my own DVD (Introduction to river fly fishing:
Spiders Plus - Online shopping - Your chosen fly Details. DVD -) and I would also recommend booking JT (on the forum and
Welcome to John Tyzack Fly Fishing) for a day or two of guiding/instruction. John is also an AAPGAI qualified casting coach.
Do also help to ensure that you have wild trout and grayling to actually fish for by supporting the Wild Trout Trust (this also plugs you into a great community of wild trout anglers).
Wild Trout Trust.
The annual mag is a great read too (probably contains about 4 or 5 issues-worth of articles compared to the monthly mainstream magazines).
Good luck with your ventures into flyfishing
Paul