Whats your budget for your build?
I've just built up a 07 python so I've got some recommendations for parts but it all comes down to the amount of cash available. If your just starting trials then you want to be looking more towards strength over light parts to begin with as you'll probably be bashing it about a bit as you learn stuff.
As a half decent spec starter bike here's what I'd recommend;
Forks - echo urbans disc + maggie mount
headset - fsa pig
stem - trialtech race forged
bars - 2nd hand zoo risers
wheels - echo urban rims, echo TR hubs (front disc hub), double butted spokes
tyres - maxxis creepy crawlers
bottom bracket - either echo tr isis or try all isis
cranks - trialtech sport forged
freewheel - echo sl
rear cog - any really but I use a trialtech
chain - trialtech z610
brakes - magura hs33 front and rear, echo tr clamps, heatsink yellow pads
pedals - depends whether you like caged or platform so either echo tr caged or trialtech race platform
bashring - again thats purely personal preference of what you like the look of but the tartybikes ones are good
snailcams - echo tr
Bearing in mind this list is mainly based roughly on my own build as I have only just got into riding a mod but I find it to be a good spec for starting, as you get better and break stuff swap it for for higher quality/lighter kit.
And I've put disc and maggie forks as it may be a good idea to start with a front magura as starting with a disc you might find yourself hitting it a lot when you learn to sidehop up stuff whereas a magura wouldn't have that problem and again you've got the option to upgrade at a later date thanks to the forks and hub!
You should also be covered for riding street as well as a bit of natural with this build.
Hope this helps you out mate and I've not completely bored you reading it!!