MCU

Hi all, this is the question: which is the fastest method to exchange informations between two 8-bit mcus?

I'm developing a tacho unit for a friend's go-kart. As long as I'm planning to use multiplexed 7-segment displays, I want to dedicate one micro to the multiplexing job and the other one will perform measurements and other operations ( the tacho is only a part of the things I want put on the kart )... maybe I'll use two PIC16f877a.

To have all finally working, I nedd them to comunicate, with the one telling the speed to the other. My ideas were:

Dear Robot enthusiasts,

Hello all!  This is my first question on here so please feel free to critique my writing style.  

So :)

There seems to be a good ammount of people here from both the picaxe and arduino camps, im an arduino man myself and havent really played with any pic kits.

What id like to know is if there is any advantage with one over the other, or even any other alternatives?

Whats your preference on things?  

There is an excellent company in my country (Serbia) which specialises in developing MCU development boards. These boards all include the following :

-In Circuit Debugger (ICD)

-Simulation components (LEDs, LCDs, 7seg displays, pull up/down buttons, keypads, thermometers, A/D,D/A.

-Easy to test interfaces (for MCU-PC interaction) such as USB, PS/2,  parrallel port, ethernet, etc

-Ability to program various families of MCUs (but for only one type, eg PICs). They usually support around five different types of MCUs per board.