First off you will need some kind of an interface card. Might I save you a lot of time and suggest you go this route.
Leo's Cards are Easy to setup, and work flawlessly. First and foremost this is going to be the easiest, and cheapest method.
Next be sure you have a registered copy of FSUIPC because it is required anyway, as this is the interface you will use to program the function's of Leo's card in Flight simulator.
you can connect up to 32 switches, and 8 potentiometers to this card, in case you decide to build your own Yoke after your throttle project, you will still be able to add more pots.
To make things easy on you for the reversers.. you can bury one of these in the throttle handles, and have your reverser's bolted to them with a little cam on them that pushed this button when they are lifted. This switch could be programmed through FSUIPC to send the F2 keystroke while held and F3 once when released to engage the reverser's when lifted, and when lowered it will disengage the reverser's.
Just a thought, much easier to implement then a pot for the reverser's.
Any 50 or 100K slide pots will work. I would suggest getting linear pots, but thats just my theory. Connect your throttle handles to the pots using old metal coat hangers through the bottom of each lever, and you can brace your handles with a through bolt going through all off them at the mid point. Just play around with things and make 3 or 4 models out of scrap until you get the right mixture. Heck if you have any Meccano or Lego use that to play with.