Sure yer. Overclocking really isn't that hard anyways (well for up to a certain level).
The boards I mentioned in two posts above (gigabyte ud3h and ud4h) will do for a decent amount of clocking, this board in particular is quite highly recommended;
http://www.overclockers.co.uk/showproduct.php?prodid=MB-434-GI&groupid=701&catid=5&subcat=2574
As for a better cooler well then your coming to high end air coolers something like;
http://www.overclockers.co.uk/showproduct.php?prodid=HS-011-NC&groupid=701&catid=2330&subcat=2346
Or closed loop water cooling units such as;
http://www.overclockers.co.uk/showproduct.php?prodid=HS-015-CS&groupid=701&catid=2330&subcat=2262
As for spending the extra money on the parts listed, that's up to you buddy. If you are not going to overclock the extra will be mostly wasted, the mobo we originally talked about will let you overclock and is a decent board, but the other ones mentioned are well just...better.
(hint again; look on the rainforest named site for Gigabyte Z87X-UD4H)
As for the better heatsinks cooling. I personally prefer high-end air cooling over Closed looped watercooling (like the one I listed above) but thats just me. Sure you have a huge chunk of metal hanging off your motherboard but better than some plastic holding water!
Either way high end air or closed loop will both do the job of keeping things cool, and both have there own pros and cons!
Just as a note, check the product dimensions for heatsinks/etc and make sure it will fit in the case you decide on!
For the added price of the motherboard or extra cooling you could get the 4770k the original motherboard and down the road if you decided to overclock you could always pick up a better aftermarket cooler! However that said I think what it comes down to is setting yourself a budget and sticking to it.
If it was me? Id get;
The 290 you got.
The money saved from the original 780, put it towards a 4770k
Decent ish motherboard like the above mentioned Gigabyte Z87X-UD4H from the rainforest named website (A LOT cheaper than here currently, sorry OCUK!)
Get a the cooler you have listed and if you do decide to overclock later on get a better high end aircooler.
The same Ram we discussed/you have listed.
the 4770k (or 4670k admittedly), coupled with a r9 290 will make for a monster.