Where can I find a fan (100cfm-ish) for this closet setup?

I've currently set up a closet for veg, and need some direction on what type of exhaust fan I should use for cooling, and where to buy it? (see photo/drawing below). The room is 90sq/ft, so I'd like to shoot for the range of 100cfm, but it seems like most centrifugal fans are 150cfm and up (and a bit pricey). I have a 4bulb, 4ft, t5 HO lamp in there, an a couple 32w t8 bulbs up top for clones.

With no ventilation (and no plants ), the temp at the top of the closet currently hits 90degF after a couple hours. I want a fan that is easy to mount to the outside of the closet door, at top, to exhaust. I'll see if the gap at the bottom of the door is enough for a passive intake, and if not, I'll cut one.

Any recommendations on where I should look online, and what type of fan? I figured centrifugal, but if I could find something that easily mounts to door, that would be a lot better. Thanks!

Inline booster fan is enough for you I bet and they are cheap and move slowly so also quite even just wrapping in duct tape to insulate from vibrating on the door will likely be enough to kill most the sound. Little tiny fan means you want to direct the air that is being sucked in down low. Even a few pieces of tape near the top of the door jam will work, remember path of least resistance is where the air will suck back in from.. (Again low where the air is coolest)

Edit: I quickly Googled for you I have no idea about the quality of this cheapie fan but I bet it is fine. I'd do a little searching before purchasing this is proof of concept
http://www.ebay.com/itm/like/111862467745?lpid=82&chn=ps&ul_noapp=true

Nice - thanks MeJuan. I saw those at the local hardware store, and was wondering if they were appropriate.

You make a good point on passive intake though, with slow air movement. Glad you brought that up. I was considering adding some ducting to inside of door that directed the incoming air in two directions (see photo/drawing). Maybe I should proceed with some sort of passive intake port considering low cfm.

If its just a veg area and you don't plan on putting adding any filters to the fan then I'd suggest using a PC fan. They're cheap and do the job well as long as they don't have any resistance.

I've heard a lot of conflicting reviews on inline booster fans. I got an all metal Bloomtek (I think that was the brand) inline booster fan and the thing sounds like a lawn mower. You could probably get 2 PC fans for the price of one duct booster.

Duct boosters function similarly to PC fans, they work fine as long as there's no pressure.
https://www.amazon.com/gp/aw/d/B009OWRMZ6/ref=mp_s_a_1_10?ie=UTF8&qid=1467656656&sr=8-10&pi=AC_SX236_SY340_QL65&keywords=ac+infinity

My suggestion is go with a larger fan and controller, as you never know what the future may hold... and once plants go in the humidity will climb so having the flexibility may help later... https://www.amazon.com/Apollo-Horticulture-Inline-Variable-Controller/dp/B019INGAF8/ref=sr_1_5?ie=UTF8&qid=1467656928&sr=8-5&keywords=exhaust+fan+with+controller... there are others too, but this wasnt so pricey or even cheaper.. https://www.amazon.com/Apollo-Horticulture-Inline-Variable-Controller/dp/B019INGAO4/ref=sr_1_14?ie=UTF8&qid=1467656928&sr=8-14&keywords=exhaust+fan+with+controller

Awesome! Thanks so much Federson, Mount, and MeJuana! I am feeling the same way about the Booster fan - it will probably do the job, but if I want to MOVE air, then I can be confident if I get a centrifugal fan.

Mount - those links are perfect! I think I'll probably go with the 190cfm 4" fan. I like the controller too, as my basement gets pretty cool in the winter months, and it will be great to have control.

Parts are inbound. I decided to start with the inline fan with speed controller, as it was pretty cheap ($20 for fan). Also, my design will allow for easily swapping out fans, so no biggie if I need to upgrade.

Will post photos when done.

Walmart sell clip on fans for 12 dollars.. Pretty cool

I first bought an inline fan for $20 that claimed it did 115cfm, but it didn't do much to bring down the temp. Was getting up to 90deg. So I bought a 4" Hurricane centrifugal fan for $75.

I initially mounted the Hurricane to the door, but it made a lot of noise. Moved it to the floor and it's pretty quiet now. The Temps stay in the upper 70's or around 80, depending on the temp of the room outside closet. Good to go though!

The t5 lamp puts out more heat than I though it would.