I think both Kelvin and Gary have hit the nail on the head. I did exactly what you're thinking of anavfan. I've got an X35 and bought a Lumagen Radiance, chromapure and an i1pro in Feb.
There's a wealth of information and tutorials out there, I'd suggest spending a couple of weekends reading the chromapure and Lumagen manuals as well as some of the 'calibration for dummies' threads. That'll give you a good idea of the tools, processes and issues others have faced when starting out.
You can just plug it all in and run an autocal, but you won't (in my experience al least) get anywhere near the perfect results you see in the advertisements. You do need to spend a good few hours learning the craft. The learning curve is steep, but well documented.
Be aware that Lumagens are aimed at the prosumer/pro install market. The menus are text based, infinitely configurable and incredibly flexible/powerful. You don't get wizards and little Microsoft dogs wagging their tails and offering to help set it up. You need to have some idea what you want it to do, how, and when.
Having said all that, after a good few hours of reading and practising the manual tweaks on my plasma to save bulb hours (and sanity, sat it the dark being hypnotised by autocal lighting up the house with flashing colours!) I'm very happy with the results.
To my surprise it's really brought new life into my 5 year old Panasonic plasma, not the main reason I bought it all, but the solidity of the image and increase in depth of field I've got has really impressed. Whether it's the deinterlacing, the dead flat gamma or the spot on colours I'm not sure but it looks flaming fantastic!
I'm very happy with my decision, especially as I know I'll get the benefit for years to come as even when I upgrade my TV HD broadcasts will still be in 1080i for years to come.
If you like absorbing your self in all the ins and outs (Linux user?

) you'll love it. If you're more of an Apple plug n play type of person you may find it an uphill battle.
You could give Gordon (convergent av) or Ricky at Kalibrate a ring and see what they'd quote for a full calibration - it will be better then your or my efforts, even after you've practised!