You can use a plate chiller with just gravity. Saves involving pimps. Here's the plumbing:
Boiler, chiller and FVI think it is good to have a reasonable drop from the chiller into your FV, as this helps to suck the wort through the chiller. Also having a valve on the outlet of the chiller helps to throttle back the wort flow to regulate cooling. I have found that the lowest I can get the temp with an acceptable flowrate is ~27C, so I tend to do the final cooling to pitch temp in a small chest freezer.
It's important to ensure the chiller is sanitary before use. I autoclave mine (and the tube \ fittings), but you could boil it or recirc hot wort \ water through it (pump needed). I also flush with hot water *immediately* after use.
When you say it's "small" - how many plates \ Kw rating?
cheers
steve