What parts do i need to buy ?

I am about to buy my first Arduino board and shield

i want to be able to read a very fast rpm - up to 50,000 rpm i want to be able to control a motor to limit the engine speed, 12 v - maybe upgrade this to 32 amps 240 v in the future

which arduine and shield do i need to buy ?

do i need an Uno ?

Thanks in advance

thanks for the reply

I want to be able to control a DC motor

that motor could be 12V and approx 20 amps

or that motor could run 240 VAC converted to DC at up to 32 amps

I am thinking i probably need to think about using a solid state relay to switch the duty cycle of the higher voltage

is there a shield that lends itself to PWM ?

where should i buy the arduino from - are clones ok ?

Thanks for the info - those boards look really good

can i use an arduino to control them ?