It all depends on driving preference (i like to drive from the rear) and track conditions

im running 7/20/3 f/c/r and find i still need to up the front a little, prolly settle for 10/20/3 its quite hard to work out whats what with the diff oils as having too much power to the back wheels will make the trucks front wheels raise and unload them which inturn creates front ballooning(most people would pressume its was to low a centre oil when actually to heaviy an oil).... like wise running low oils in the front and centre will also create balloning from pure power rather than the wheelying effect i like to think of it this way:-

Centre diff allows power shift between front and rear wheels as a pair. front and rear diff should be used to control side to side power on them said wheels....

I.e if when cornering left, ONLY the front left wheel balloons then you prolly want to stiffen ONLY the front diff. If however both front wheels balloon then you want to first stiffen the centre diff. This is only a rule of thumb theres lots of room for scope but this will help you BALANCE the power to your liking....

Shocks again its all trial and error. Too stiff at the back and you get wheelies and power sliding. Too soft and you get chassis slap and unstable driving. i went for 45fr and 40r and find it too slow with the stock pistons... i need to fine tune when i get some spare time but mine tends to pack too easily on fast bumpy stuff. Loves the big jumps though. Its all about finding the happy medium. I'll prolly drill some holes bigger in the pistons and stick with the oil i have. Would just like it to return a little quicker.

I run my truck stock for a gallon just to let it settle down and bed in. Get used to what its doing and try and look carefully and decide if the shocks are too loose and return to quickly and keep an eye on what tires are ballooning and when. Is it when on full power and the back sits down you get balloning on both the fronts etc etc. Im no expert but i have run trucks previosuly for long time and kinda know what i want from my truggy and how i want it to handle. I also tend to only bash but i would call it pretty much extreme with big jumps and skate parks. I also use a tight tarmac track locally as well as a bmx dirtjump area... therefore i need a good reliable ALLROUNDER setup.

Remeber you can always mix oils to thicken and thin them down so buy maybe 3 diff like 3/20/7 obviously you cant mix below 3000wt but you can easily mix 7 with 20 and get near 10k wt not a problem.... same with the shocks 30 70 and 40. you can make plenty of combos from them and i havent seen many run less than 30wt anyways.