If money is not an issue just get the Thrustmaster Warthog and be done with it. As far as pedals go you can choose between CH and Saitek - the quality of both is similar but the CH pedals tend to be closer together. It just depends on what's most comfortable for you.
If money is an issue then keep the X52 throttle and get a decent twisty stick or a CH stick and your choice of pedals.
You can use the X52 throttle by itself and the CH throttle really has little to add function-wise... so really the only reason to buy a CH throttle would be if you wanted a matching set.
As far as the G940 goes... well I can't recommend it. Don't get me wrong I love mine as the force feedback is very nice but it just burns my britches to see how Logitech bastardized what could have easily been the king of HOTAS setups. You can get a used set real cheap right now (don't waste money on new because you'll be wanting to void the warranty anyway) and it can end up being a nice stick for you if you like to tinker but don't expect to be happy with it as-is.
There are three major flaws that plague the G940:
1> The wiring in the throttle is way to fragile and about 1/8" too short. It takes only a couple of months of the wiring flexing back and forth to break it. I ended up completely disassembling my throttle and rewiring it. This isn't a matter of "if" it fails.. it's a matter of "when". Expect to be disappointed by sending your unit in and having the warranty replacement fail after only a couple of months.
2> Logitech has a "hysteresis" programmed into the stick's firmware which makes it way too imprecise. Logitech (for the most part) issued a firmware update that fixes this in the stick's X and Y axes but have done nothing to correct all of the other axes. I ended up getting around this by rewiring the throttle's and the rudder's axes into a third party controller board. Expect precision of the rudders, trims, and throttles to be very poor unless you're willing to do this as well.
3> Some people have reported the potentiometer in the rudders failing prematurely however mine has worked flawlessly. It can be replaced with a quality CH pot relatively inexpensively (and quite easily).
It's a shame too because otherwise the quality is pretty good and the Force Feedback is very, very nice. Had Logitech spent an extra $2 per unit on parts and hired engineers who gave a rat's backside it could have easily been sold for $350 and people would be lined up to pay that kind of money for it. It could have revived Logitech's reputation in the flight sim community but obviously this wasn't the case. Instead Logitech turned their backs on us and refuse to support the product any further (aside from honoring the 12 month hardware warranty by replacing it with another defective unit).
I bought my G940 knowing of its issues but I couldn't resist the sale price of $200 brand new from Amazon about 15 months ago. It looks like it's going for $250 now (
CLICK HERE). I really hoped that people were overreacting about it but I soon found out it was worse than I thought. I'm SO GLAD I didn't pay the $300+ retail price for it because it cost me another $50-60 in parts to fix the thing! But like I said... if you like to tinker and you want a fun project then do yourself a favor and find a cheap used one and tear it apart!
You can find details about my modifications here:
http://simhq.com/forum/ubbthreads.php/topics/3330772/1.html