How to setup a UV?? And bulb question

I'll skip the bulb question (LOL) but can comment immedaitely re: the install itself. You have a few options here:

Option 1) You can install such units inline with the intake or output tubing of your filter. Many select this option but it can be difficult to match up the tubing ID (internal diameter) of the units. FX5's use a 1" ID; there is a strong probability that this is larger than your UV unit. Regardless, the FX5 in particular is a bit finicky with inline installs. The auto-purge feature of the unit appears to be sensitive to any branching in any of the tubing and I've heard some horror stories form those who've attempted it (i.e. unit malfunction).

Option 2) Use a submersible powerhead in the tank to pump water through a loop of tubing that includes the UV with return to the tank. Here's an example of a submersible powerhead that many can recommend:

http://www.drsfostersmith.com/product/prod_display.cfm?c=3578+4585+4609&pcatid=4609

I've personally used the the Model 1200 (295 gph) to power such a loop and it had more than enough juice to power a long tubing loop for my 125 gallon. The primary downside for these submersibles is that they generate heat and can raise the temp. of your tank + there's an ugly powerhead in your tank. Otherwise, this is typically a reliable and easy solution.

Option 3) Instead of using a submersible unit, you can use a "hobby" pump for an inline install on a separate tubing loop similar to the one you make for the submersible unit. Here's an example unit:

http://www.drsfostersmith.com/product/prod_display.cfm?c=3578+4585+4604&pcatid=4604

I personally find this option a bit cumbersome and the units can be noisy. Nevertheless, it will still get the job done.

Option 4) My personal favorite (and its under-utilized) is to use a dedicated smaller filter to power the unit. I happen to have an FX5 on my 125 gallon planted. My 25W gamma UV Sterilizer is powered via a tubing loop with a Fluval 205! It has more than enough gas to drive the loop and the extra filtration/biomedia never hurts. FYI I also have my pressurized CO2 injection/bio-reactor on the outlet side of the same filter loop. This is not the least expensive option available but I found it the easiest and most robust solution for my tank. Easy maintenance, simple priming with the Fluval models and plenty of power to drive the loop.

For all of these installs, it is critical that you match up the ID inlet/outlet of all units to ensure compatibility; there is nothing more frustrating than buying a pump + tubing only to find that your UV unit uses a different size. A little bit of advance research is required

EDIT: If you use the small Fluval filter method, realize you will NOT be using the stock ribbed tubing that comes with the unit. Instead, you'll be buying the appropriate sized tubing and using that instead. Get ready, because plumbing these loops is always a pain in the _____ (but it is well worth it).

I can't address the bulb question but I am using a Maxi-jet 1200 internal pump in a lupe with a gamma 25 watt UV sterilizer and it works great.

I thought the flow rate needed to be slower to allow the UV to kill stuff? I'm just starting to look into it.

Each UV steralizer has different specs for water flow based on what you are trying to kill. The slower and longer the water stays in the steralizer the longer it is exposed to the UV light thus killing algae, bateria, or steralizing the water completely.

I'm using a Rio 1700 to power my Aqua 8W UV. It works well but is a bit bulky in the corner of my tank. Very cost effective and allows me to control the flow through the steralizer.