As GCR said, drop the res, lots of people include them and people have this idea that they are necessary, but they are a convenience(Ease of filling) only. A t-line is simply a three way t-shaped hose barb placed somewhere in the loop. (Its a good idea to place it right before the pump inlet, but often that conflicts with the desire of many to place it as high in the loop as possible, which aids bleeding.) From the 3rd prong of the T you just run a short length of tubing and put and end-cap on it. This short piece of tubing is in effect the res.
In addition to GCR's comments I would suggest you use masterkleer tubing, as tygon will be out of your price range. You can save a whole lot of money on the radiator by not buying one made for the purpose. Look online at the dimensions of automotive AC-Unit heatercores, and find one that is suitably thin and of the correct dimensions to fit either 1 or 2 120mm fans. Common usage here is the fedco 2-302 series of heatercores. They require a bit of modding, need to cut the copper tubing and thread the ports so that barbs can be installed, but if you are willing to invest the research and effort, it is very very cheap, and very effective.
For fans I would recommend Yate Loons as they are not only quiet but are generally amongst the cheapest fans available.
That pond pump is very dubious, as it proffers no specifications and is most likely all flow and no head, which can be a problem. The watercooling pump is extremely overpriced for what it is however, and you could definitely get better for your money there. Mag3, or some of the Hydor L series would do you, but really you are so close to the lower price points of the main WC pumps that it would probably be a good investment to just splurge on that and pay a little more for a d5 or a ddc, the classifieds has historically had amazing deals on used versions of these two.
Finally don't waste your money on those clamps online, go to your local hardware store and buy a bag of the same thing, in the US you can get bags of 10 for less than $2.
Good luck.